Abrasive particles having particular shapes and methods of forming such particles

ABSTRACT

An abrasive article comprising a first group including a plurality of shaped abrasive particles overlying a backing, wherein the plurality of shaped abrasive particles of the first group define a first non-shadowing distribution relative to each other.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 15/223,701, entitled “ABRASIVE PARTICLES HAVINGPARTICULAR SHAPES AND METHODS OF FORMING SUCH PARTICLES,” by inventorsAnthony C. GAETA et al., filed on Jul. 29, 2016, which is a continuationof U.S. Non-Provisional patent application Ser. No. 14/054,568, now U.S.Pat. No. 9,440,332 B2, issued Sep. 13, 2016, entitled “ABRASIVEPARTICLES HAVING PARTICULAR SHAPES AND METHODS OF FORMING SUCHPARTICLES,” by inventors Anthony C. GAETA et al., filed on Oct. 15,2013, and claims priority to and the benefit of US Provisional PatentApplication(s) 61/714,028, filed on Oct. 15, 2012 and 61/747,535, filedon Dec. 31, 2012, which are incorporated herein by reference in theirentirety.

BACKGROUND

Field of the Disclosure

The following is directed to abrasive articles, and particularly,methods of forming abrasive articles.

Description of the Related Art

Abrasive particles and abrasive articles made from abrasive particlesare useful for various material removal operations including grinding,finishing, and polishing. Depending upon the type of abrasive material,such abrasive particles can be useful in shaping or grinding a widevariety of materials and surfaces in the manufacturing of goods. Certaintypes of abrasive particles have been formulated to date that haveparticular geometries, such as triangular shaped abrasive particles andabrasive articles incorporating such objects. See, for example, U.S.Pat. Nos. 5,201,916; 5,366,523; and 5,984,988.

Some basic technologies that have been employed to produce abrasiveparticles having a specified shape are (1) fusion, (2) sintering, and(3) chemical ceramic. In the fusion process, abrasive particles can beshaped by a chill roll, the face of which may or may not be engraved, amold into which molten material is poured, or a heat sink materialimmersed in an aluminum oxide melt. See, for example, U.S. Pat. No.3,377,660, disclosing a process comprising the steps of flowing moltenabrasive material from a furnace onto a cool rotating casting cylinder,rapidly solidifying the material to form a thin semisolid curved sheet,densifying the semisolid material with a pressure roll, and thenpartially fracturing the strip of semisolid material by reversing itscurvature by pulling it away from the cylinder with a rapidly drivencooled conveyor.

In the sintering process, abrasive particles can be formed fromrefractory powders having a particle size of 45 micrometers or less indiameter. Binders can be added to the powders along with a lubricant anda suitable solvent, e.g., water. The resulting mixtures, or slurries canbe shaped into platelets or rods of various lengths and diameters. See,for example, U.S. Pat. No. 3,079,242, which discloses a method of makingabrasive particles from calcined bauxite material comprising the stepsof (1) reducing the material to a fine powder, (2) compacting underaffirmative pressure and forming the fine particles of said powder intograin sized agglomerations, and (3) sintering the agglomerations ofparticles at a temperature below the fusion temperature of the bauxiteto induce limited recrystallization of the particles, whereby abrasivegrains are produced directly to size.

Chemical ceramic technology involves converting a colloidal dispersionor hydrosol (sometimes called a sol), optionally in a mixture, withsolutions of other metal oxide precursors, to a gel drying, and firingto obtain a ceramic material. See, for example, U.S. Pat. Nos. 4,744,802and 4,848,041.

Still, there remains a need in the industry for improving performance,life, and efficacy of abrasive particles, and the abrasive articles thatemploy abrasive particles.

SUMMARY

According to a first aspect, an abrasive article includes a backing, anadhesive layer overlying the backing, a first shaped abrasive particlecoupled to the backing in a first position, a second shaped abrasiveparticle coupled to the backing in a second position, and wherein thefirst shaped abrasive particle and second shaped abrasive particle arearranged in a non-shadowing arrangement relative to each other, thenon-shadowing arrangement comprising at least two of a predeterminedrotational orientation, a predetermined lateral orientation, and apredetermined longitudinal orientation.

In yet another aspect, an abrasive article includes a backing, anadhesive layer overlying the backing, a first group comprising aplurality of shaped abrasive particles coupled to the backing, whereineach of the plurality of shaped abrasive particles of the first groupshare at least one of a predetermined rotational orientation, apredetermined lateral orientation, and a predetermined longitudinalorientation, and a second group comprising a plurality of shapedabrasive particles distinct from the first group and coupled to thebacking, wherein each of the plurality of shaped abrasive particles ofthe second group share at least one of a predetermined rotationalorientation, a predetermined lateral orientation, and a predeterminedlongitudinal orientation.

For another aspect, an abrasive article includes a backing, and a firstgroup comprising a plurality of shaped abrasive particles coupled to thebacking in a discontinuous layer, the plurality of shaped abrasiveparticles arranged in a non-shadowing arrangement with respect to eachother and defining a same rotational orientation, a same lateralorientation, a same lateral orientation space, a same longitudinalorientation, and a same longitudinal orientation space.

According to one aspect, an abrasive article includes a first groupincluding a plurality of shaped abrasive particles overlying a backing,wherein the plurality of shaped abrasive particles of the first groupdefined a first pattern relative to each other.

For still another aspect, an abrasive article includes a backing and afirst group having a plurality of shaped abrasive particles coupled tothe backing in a discontinuous layer, the plurality of shaped abrasiveparticles of the first group defined by a combination of at least two ofa same predetermined rotational orientation, a same predeterminedlateral orientation, a same predetermined longitudinal orientation, asame predetermined vertical height, and a same predetermined tip height.

According to one aspect, an abrasive article includes a plurality ofshaped abrasive particles of a first group overlying a backing, whereinthe plurality of shaped abrasive particles of the first group define anon-shadowing arrangement relative to each other, and wherein at leastabout 80% of a total content of the shaped abrasive particles arearranged in a side orientation relative to the backing.

In a certain aspect, a method of forming an abrasive article includesproviding a backing, placing a first shaped abrasive particle on thebacking in a first position defined by at least two of a predeterminedrotational orientation, a predetermined lateral orientation, and apredetermined longitudinal orientation, and placing a second shapedabrasive particle on the backing in a second positioned defined by atleast two of a predetermined rotational orientation, a predeterminedlateral orientation, and a predetermined longitudinal orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1A includes a top view illustration of a portion of an abrasivearticle according to an embodiment.

FIG. 1B includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment.

FIG. 1C includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment.

FIG. 1D includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment.

FIG. 2A includes a top view illustration of a portion of an abrasivearticle including shaped abrasive particles in accordance with anembodiment.

FIG. 2B includes a perspective view of a shaped abrasive particle on anabrasive article in accordance with an embodiment.

FIG. 3A includes a top view illustration of a portion of an abrasivearticle in accordance with an embodiment.

FIG. 3B includes a perspective view illustration of a portion of anabrasive article including shaped abrasive particles havingpredetermined orientation characteristics relative to a grindingdirection in accordance with an embodiment.

FIG. 4 includes a top view illustration of a portion of an abrasivearticle in accordance with an embodiment.

FIG. 5 includes a top view of a portion of an abrasive article inaccordance with an embodiment.

FIG. 6 includes a top view illustration of a portion of an abrasivearticle in accordance with an embodiment.

FIG. 7A includes a top view illustration of a portion of an abrasivearticle in accordance with an embodiment.

FIG. 7B includes a perspective view illustration of a portion of anabrasive article in accordance with an embodiment.

FIG. 7C includes a top view illustration of a non-shadowing arrangementto be formed on a portion of an abrasive article is provided inaccordance with an embodiment.

FIG. 7D includes an image of a portion of an abrasive article having anon-shadowing arrangement of shaped abrasive particles in accordancewith an embodiment.

FIG. 8A includes a perspective view illustration of a shaped abrasiveparticle in accordance with an embodiment.

FIG. 8B includes a cross-sectional illustration of the shaped abrasiveparticle of FIG. 8A.

FIG. 8C includes a side-view illustration of a shaped abrasive particleaccording to an embodiment.

FIG. 9 includes an illustration of a portion of an alignment structureaccording to an embodiment.

FIG. 10 includes an illustration of a portion of an alignment structureaccording to an embodiment.

FIG. 11 includes an illustration of a portion of an alignment structureaccording to an embodiment.

FIG. 12 includes an illustration of a portion of an alignment structureaccording to an embodiment.

FIG. 13 includes an illustration of a portion of an alignment structureincluding discrete contact regions comprising an adhesive in accordancewith an embodiment.

FIGS. 14A-14H include top down views of portions of tools for formingabrasive articles having various patterned alignment structuresincluding discrete contact regions of an adhesive material according toembodiments herein.

FIG. 15 includes an illustration of a system for forming an abrasivearticle according to an embodiment.

FIG. 16 includes an illustration of a system for forming an abrasivearticle according to an embodiment.

FIGS. 17A-17C include illustrations of systems for forming an abrasivearticle according to an embodiment.

FIG. 18 includes an illustration of a system for forming an abrasivearticle according to an embodiment.

FIG. 19 includes an illustration of a system for forming an abrasivearticle according to an embodiment.

FIG. 20A includes an image of a tool used to form an abrasive articleaccording to an embodiment.

FIG. 20B includes an image of a tool used to form an abrasive articleaccording to an embodiment.

FIG. 20C includes an image of a portion of an abrasive article accordingto an embodiment.

FIG. 21 includes a plot of normal force (N) versus cut number for SampleA and Sample B according to the grinding test of Example 1.

FIG. 22 includes an image of a portion of an exemplary sample accordingto an embodiment.

FIG. 23 includes an image of a portion of a conventional sample.

FIG. 24 includes a plot of up grains/cm² and total number of grains/cm²for two conventional samples and three sample representative ofembodiments.

FIGS. 25-27 include illustrations of plots of locations of shapedabrasive particles on a backing to form non-shadowing arrangementsaccording to embodiments.

FIG. 28 includes an illustration of a plot of locations of shapedabrasive particles on a backing to form non-shadowing arrangementsaccording to an embodiment.

FIG. 29 includes an image of a conventional sample having a shadowingarrangement of shaped abrasive particles on the backing.

FIG. 30 includes an image of a portion of a surface of a workpieceground using a sample representing an embodiment.

FIG. 31 includes an image of a portion of a surface of a workpieceground using a sample representing a conventional embodiment.

FIG. 32 includes images representative of portions of a coated abrasiveaccording to an embodiment.

DETAILED DESCRIPTION

The following is directed to methods of forming shaped abrasiveparticles, features of shaped abrasive particles, methods of formingabrasive articles using shaped abrasive article, and features ofabrasive articles. The shaped abrasive particles may be used in variousabrasive articles, including for example bonded abrasive articles,coated abrasive articles, and the like. In particular instances, theabrasive articles of embodiments herein can be coated abrasive articlesdefined by a single layer of abrasive grains, and more particularly adiscontinuous, single layer of shaped abrasive particles, which may bebonded or coupled to a backing and used to remove material fromworkpieces. Notably, the shaped abrasive particles can be placed in acontrolled manner such that the shaped abrasive particles define apredetermined distribution relative to each other.

Methods of Forming Shaped Abrasive Particles

Various methods may be employed to form shaped abrasive particles. Forexample, the shaped abrasive particles may be formed using techniquessuch as extrusion, molding, screen printing, rolling, melting, pressing,casting, segmenting, sectioning, and a combination thereof. In certaininstances, the shaped abrasive particles may be formed from a mixture,which may include a ceramic material and a liquid. In particularinstances, the mixture may be a gel formed of a ceramic powder materialand a liquid, wherein the gel can be characterized as a shape-stablematerial having the ability to substantially hold a given shape even inthe green (i.e., unfired) state. In accordance with an embodiment, thegel can be formed of the ceramic powder material as an integratednetwork of discrete particles.

The mixture may contain a certain content of solid material, liquidmaterial, and additives such that it has suitable rheologicalcharacteristics for forming the shaped abrasive particles. That is, incertain instances, the mixture can have a certain viscosity, and moreparticularly, suitable rheological characteristics that facilitateformation a dimensionally stable phase of material. A dimensionallystable phase of material is a material that can be formed to have aparticular shape and substantially maintain the shape such that theshape is present in the finally-formed object.

According to a particular embodiment, the mixture can be formed to havea particular content of solid material, such as the ceramic powdermaterial. For example, in one embodiment, the mixture can have a solidscontent of at least about 25 wt %, such as at least about 35 wt %, oreven at least about 38 wt % for the total weight of the mixture. Still,in at least one non-limiting embodiment, the solid content of themixture can be not greater than about 75 wt % such as not greater thanabout 70 wt %, not greater than about 65 wt %, not greater than about 55wt %, not greater than about 45 wt %, or not greater than about 42 wt %.It will be appreciated that the content of the solids materials in themixture can be within a range between any of the minimum and maximumpercentages noted above.

According to one embodiment, the ceramic powder material can include anoxide, a nitride, a carbide, a boride, an oxycarbide, an oxynitride, anda combination thereof. In particular instances, the ceramic material caninclude alumina. More specifically, the ceramic material may include aboehmite material, which may be a precursor of alpha alumina. The term“boehmite” is generally used herein to denote alumina hydrates includingmineral boehmite, typically being Al₂O₃.H₂O and having a water contenton the order of 15%, as well as psuedoboehmite, having a water contenthigher than 15%, such as 20-38% by weight. It is noted that boehmite(including psuedoboehmite) has a particular and identifiable crystalstructure, and accordingly unique X-ray diffraction pattern, and assuch, is distinguished from other aluminous materials including otherhydrated aluminas such as ATH (aluminum trihydroxide) a common precursormaterial used herein for the fabrication of boehmite particulatematerials.

Furthermore, the mixture can be formed to have a particular content ofliquid material. Some suitable liquids may include water. In accordancewith one embodiment, the mixture can be formed to have a liquid contentless than the solids content of the mixture. In more particularinstances, the mixture can have a liquid content of at least about 25 wt%, such as at least about 35 wt %, at least about 45 wt %, at leastabout 50 wt %, or even at least about 58 wt % for the total weight ofthe mixture. Still, in at least one non-limiting embodiment, the liquidcontent of the mixture can be not greater than about 75 wt %, such asnot greater than about 70 wt %, not greater than about 65 wt %, notgreater than about 62 wt %, or even not greater than about 60 wt %. Itwill be appreciated that the content of the liquid in the mixture can bewithin a range between any of the minimum and maximum percentages notedabove.

Furthermore, for certain processes, the mixture may have a particularstorage modulus. For example, the mixture can have a storage modulus ofat least about 1×10⁴ Pa, such as at least about 4×10⁴ Pa, or even atleast about 5×10⁴ Pa. However, in at least one non-limiting embodiment,the mixture may have a storage modulus of not greater than about 1×10⁷Pa, such as not greater than about 2×10⁶ Pa. It will be appreciated thatthe storage modulus of the mixture 101 can be within a range between anyof the minimum and maximum values noted above.

The storage modulus can be measured via a parallel plate system usingARES or AR-G2 rotational rheometers, with Peltier plate temperaturecontrol systems. For testing, the mixture can be extruded within a gapbetween two plates that are set to be approximately 8 mm apart from eachother. After extruding the gel into the gap, the distance between thetwo plates defining the gap is reduced to 2 mm until the mixturecompletely fills the gap between the plates. After wiping away excessmixture, the gap is decreased by 0.1 mm and the test is initiated. Thetest is an oscillation strain sweep test conducted with instrumentsettings of a strain range between 01% to 100%, at 6.28 rad/s (1 Hz),using 25-mm parallel plate and recording 10 points per decade. Within 1hour after the test completes, lower the gap again by 0.1 mm and repeatthe test. The test can be repeated at least 6 times. The first test maydiffer from the second and third tests. Only the results from the secondand third tests for each specimen should be reported.

Furthermore, to facilitate processing and forming shaped abrasiveparticles according to embodiments herein, the mixture can have aparticular viscosity. For example, the mixture can have a viscosity ofat least about 4×10³ Pa s, at least about 5×10³ Pa s, at least about6×10³ Pa s, at least about 8×10³ Pa s, at least about 10×10³ Pa s, atleast about 20×10³ Pa s, at least about 30×10³ Pa s, at least about40×10³ Pa s, at least about 50×10³ Pa s, at least about 60×10³ Pa s, atleast about 65×10³ Pa s. In at least one non-limiting embodiment, themixture may have a viscosity of not greater than about 100×10³ Pa s, notgreater than about 95×10³ Pa s, not greater than about 90×10³ Pa s, oreven not greater than about 85×10³ Pa s. It will be appreciated that theviscosity of the mixture can be within a range between any of theminimum and maximum values noted above. The viscosity can be measured inthe same manner as the storage modulus as described above.

Moreover, the mixture can be formed to have a particular content oforganic materials, including for example, organic additives that can bedistinct from the liquid, to facilitate processing and formation ofshaped abrasive particles according to the embodiments herein. Somesuitable organic additives can include stabilizers, binders, such asfructose, sucrose, lactose, glucose, UV curable resins, and the like.

Notably, the embodiments herein may utilize a mixture that can bedistinct from slurries used in conventional forming operations. Forexample, the content of organic materials, within the mixture,particularly, any of the organic additives noted above, may be a minoramount as compared to other components within the mixture. In at leastone embodiment, the mixture can be formed to have not greater than about30 wt % organic material for the total weight of the mixture. In otherinstances, the amount of organic materials may be less, such as notgreater than about 15 wt %, not greater than about 10 wt %, or even notgreater than about 5 wt %. Still, in at least one non-limitingembodiment, the amount of organic materials within the mixture can be atleast about 0.01 wt %, such as at least about 0.5 wt % for the totalweight of the mixture. It will be appreciated that the amount of organicmaterials in the mixture can be within a range between any of theminimum and maximum values noted above.

Moreover, the mixture can be formed to have a particular content of acidor base distinct from the liquid, to facilitate processing and formationof shaped abrasive particles according to the embodiments herein. Somesuitable acids or bases can include nitric acid, sulfuric acid, citricacid, chloric acid, tartaric acid, phosphoric acid, ammonium nitrate,ammonium citrate. According to one particular embodiment, the mixturecan have a pH of less than about 5, and more particularly, within arange between about 2 and about 4, using a nitric acid additive.

According to one particular method of forming, the mixture can be usedto form shaped abrasive particles via a screen printing process.Generally, a screen printing process may include extrusion of themixture from a die into openings of a screen in an application zone. Asubstrate combination including a screen having openings and a beltunderlying the screen can be translated under the die and the mixturecan be delivered into the openings of the screen. The mixture containedin the openings can be later extracted from the openings of the screenand contained on the belt. The resulting shaped portions of mixture canbe precursor shaped abrasive particles.

In accordance with an embodiment, the screen can have one or moreopenings having a predetermined two-dimensional shape, which mayfacilitate formation of shaped abrasive particles having substantiallythe same two-dimensional shape. It will be appreciated that there may befeatures of the shaped abrasive particles that may not be replicatedfrom the shape of the opening. According to one embodiment, the openingcan have various shapes, for example, a polygon, an ellipsoid, anumeral, a Greek alphabet letter, a Latin alphabet letter, a Russianalphabet character, a Kanji character, a complex shape including acombination of polygonal shapes, and a combination thereof. Inparticular instances, the openings may have two-dimensional polygonalshape such as, a triangle, a rectangle, a quadrilateral, a pentagon, ahexagon, a heptagon, an octagon, a nonagon, a decagon, and a combinationthereof.

Notably, the mixture can be forced through the screen in rapid fashion,such that the average residence time of the mixture within the openingscan be less than about 2 minutes, less than about 1 minute, less thanabout 40 seconds, or even less than about 20 seconds. In particularnon-limiting embodiments, the mixture may be substantially unalteredduring printing as it travels through the screen openings, thusexperiencing no change in the amount of components from the originalmixture, and may experience no appreciable drying in the openings of thescreen.

The belt and/or the screen may be translated at a particular rate tofacilitate processing. For example, the belt and/or the screen may betranslated at a rate of at least about 3 cm/s. In other embodiments, therate of translation of the belt and/or the screen may be greater, suchas at least about 4 cm/s, at least about 6 cm/s, at least about 8 cm/s,or even at least about 10 cm/s. For certain processes according toembodiments herein, the rate of translation of the belt as compared tothe rate of extrusion of the mixture may be controlled to facilitateproper processing.

Certain processing parameters may be controlled to facilitate featuresof the precursor shaped abrasive particles (i.e., the particlesresulting from the shaping process) and the finally-formed shapedabrasive particles described herein. Some exemplary process parameterscan include a release distance defining a point of separation betweenthe screen and the belt relative to a point within the application zone,a viscosity of the mixture, a storage modulus of the mixture, mechanicalproperties of components within the application zone, thickness of thescreen, rigidity of the screen, a solid content of the mixture, acarrier content of the mixture, a release angle between the belt andscreen, a translation speed, a temperature, a content of release agenton the belt or on the surfaces of the openings of the screen, a pressureexerted on the mixture to facilitate extrusion, a speed of the belt, anda combination thereof.

After completing the shaping process, the resultant precursor shapedabrasive particles may be translated through a series of zones, whereinadditional treatments can occur. Some suitable exemplary additionaltreatments can include drying, heating, curing, reacting, radiating,mixing, stirring, agitating, planarizing, calcining, sintering,comminuting, sieving, doping, and a combination thereof. According toone embodiment, the precursory shaped abrasive particles may betranslated through an optional shaping zone, wherein at least oneexterior surface of the particles may be further shaped. Additionally oralternatively, the precursor shaped abrasive particles may be translatedthrough an application zone wherein a dopant material can be applied toat least one exterior surface of the precursor shaped abrasiveparticles. A dopant material may be applied utilizing various methodsincluding for example, spraying, dipping, depositing, impregnating,transferring, punching, cutting, pressing, crushing, and any combinationthereof. In particular instances, the application zone may utilize aspray nozzle, or a combination of spray nozzles to spray dopant materialonto the precursor shaped abrasive particles.

In accordance with an embodiment, applying a dopant material can includethe application of a particular material, such as a precursor. Someexemplary precursor materials can include a dopant material to beincorporated into the finally-formed shaped abrasive particles. Forexample, the metal salt can include an element or compound that is theprecursor to the dopant material (e.g., a metal element). It will beappreciated that the salt may be in liquid form, such as in a mixture orsolution comprising the salt and liquid carrier. The salt may includenitrogen, and more particularly, can include a nitrate. In otherembodiments, the salt can be a chloride, sulfate, phosphate, and acombination thereof. In one embodiment, the salt can include a metalnitrate, and more particularly, consist essentially of a metal nitrate.

In one embodiment, the dopant material can include an element orcompound such as an alkali element, alkaline earth element, rare earthelement, hafnium, zirconium, niobium, tantalum, molybdenum, vanadium, ora combination thereof. In one particular embodiment, the dopant materialincludes an element or compound including an element such as lithium,sodium, potassium, magnesium, calcium, strontium, barium, scandium,yttrium, lanthanum, cesium, praseodymium, niobium, hafnium, zirconium,tantalum, molybdenum, vanadium, chromium, cobalt, iron, germanium,manganese, nickel, titanium, zinc, and a combination thereof.

In particular instances, the process of applying a dopant material caninclude select placement of the dopant material on an exterior surfaceof a precursor shaped abrasive particle. For example, the process ofapplying a dopant material can include the application of a dopantmaterial to an upper surface or a bottom surface of the precursor shapedabrasive particles. In still another embodiment, one or more sidesurfaces of the precursor shaped abrasive particles can be treated suchthat a dopant material is applied thereto. It will be appreciated thatvarious methods may be used to apply the dopant material to variousexterior surfaces of the precursor shaped abrasive particles. Forexample, a spraying process may be used to apply a dopant material to anupper surface or side surface of the precursor shaped abrasiveparticles. Still, in an alternative embodiment, a dopant material may beapplied to the bottom surface of the precursor shaped abrasive particlesthrough a process such as dipping, depositing, impregnating, or acombination thereof. It will be appreciated that a surface of the beltmay be treated with dopant material to facilitate a transfer of thedopant material to a bottom surface of precursor shaped abrasiveparticles.

And further, the precursor shaped abrasive particles may be translatedon the belt through a post-forming zone, wherein a variety of processes,including for example, drying, may be conducted on the precursor shapedabrasive particles as described in embodiments herein. Various processesmay be conducted in the post-forming zone, including treating of theprecursor shaped abrasive particles. In one embodiment, the post-formingzone can include a heating process, wherein the precursor shapedabrasive particles may be dried. Drying may include removal of aparticular content of material, including volatiles, such as water. Inaccordance with an embodiment, the drying process can be conducted at adrying temperature of not greater than about 300° C., such as notgreater than about 280° C., or even not greater than about 250° C.Still, in one non-limiting embodiment, the drying process may beconducted at a drying temperature of at least about 50° C. It will beappreciated that the drying temperature may be within a range betweenany of the minimum and maximum temperatures noted above. Furthermore,the precursor shaped abrasive particles may be translated through thepost-forming zone at a particular rate, such as at least about 0.2feet/min (0.06 m/min) and not greater than about 8 feet/min (2.4 m/min).

In accordance with an embodiment, the process of forming shaped abrasiveparticles may further comprise a sintering process. For certainprocesses of embodiments herein, sintering can be conducted aftercollecting the precursor shaped abrasive particles from the belt.Alternatively, the sintering may be a process that is conducted whilethe precursor shaped abrasive particles are on the belt. Sintering ofthe precursor shaped abrasive particles may be utilized to densify theparticles, which are generally in a green state. In a particularinstance, the sintering process can facilitate the formation of ahigh-temperature phase of the ceramic material. For example, in oneembodiment, the precursor shaped abrasive particles may be sintered suchthat a high-temperature phase of alumina, such as alpha alumina isformed. In one instance, a shaped abrasive particle can comprise atleast about 90 wt % alpha alumina for the total weight of the particle.In other instances, the content of alpha alumina may be greater, suchthat the shaped abrasive particle may consist essentially of alphaalumina.

Shaped Abrasive Particles

The shaped abrasive particles can be formed to have various shapes. Ingeneral, the shaped abrasive particles may be formed to have a shapeapproximating shaping components used in the forming process. Forexample, a shaped abrasive particle may have a predeterminedtwo-dimensional shape as viewed in any two dimensions of the threedimension shape, and particularly in a dimension defined by the lengthand width of the particle. Some exemplary two-dimensional shapes caninclude a polygon, an ellipsoid, a numeral, a Greek alphabet letter, aLatin alphabet letter, a Russian alphabet character, a Kanji character,a complex shape including a combination of polygonal shapes, and acombination thereof. In particular instances, the shaped abrasiveparticle may have two-dimensional polygonal shape such as, a triangle, arectangle, a quadrilateral, a pentagon, a hexagon, a heptagon, anoctagon, a nonagon, a decagon, and a combination thereof.

In one particular aspect, the shaped abrasive particles may be formed tohave a shape as illustrated in FIG. 8A. FIG. 8A includes a perspectiveview illustration of a shaped abrasive particle in accordance with anembodiment. Additionally, FIG. 8B includes a cross-sectionalillustration of the shaped abrasive particle of FIG. 8A. The body 801includes an upper surface 803 a bottom surface 804 opposite the uppersurface 803. The upper surface 803 and the bottom surface 804 can beseparated from each other by side surfaces 805, 806, and 807. Asillustrated, the body 801 of the shaped abrasive particle 800 can have agenerally triangular shape as viewed in a plane defined by the uppersurface 803. In particular, the body 801 can have a length (Lmiddle) asshown in FIG. 8B, which may be measured at the bottom surface 804 of thebody 801 and extending from a corner at the bottom surface correspondingto corner 813 at the top surface through a midpoint 881 of the body 801to a midpoint at the opposite edge of the body corresponding to the edge814 at the upper surface of the body. Alternatively, the body can bedefined by a second length or profile length (Lp), which is the measureof the dimension of the body from a side view at the upper surface 803from a first corner 813 to an adjacent corner 812. Notably, thedimension of Lmiddle can be a length defining a distance between aheight at a corner (hc) and a height at a midpoint edge (hm) oppositethe corner. The dimension Lp can be a profile length along a side of theparticle defining the distance between h1 and h2 (as explained herein).Reference herein to the length can be reference to either Lmiddle or Lp.

The body 801 can further include a width (w) that is the longestdimension of the body and extending along a side. The shaped abrasiveparticle can further include a height (h), which may be a dimension ofthe shaped abrasive particle extending in a direction perpendicular tothe length and width in a direction defined by a side surface of thebody 801. Notably, as will be described in more detail herein, the body801 can be defined by various heights depending upon the location on thebody. In specific instances, the width can be greater than or equal tothe length, the length can be greater than or equal to the height, andthe width can be greater than or equal to the height.

Moreover, reference herein to any dimensional characteristic (e.g., h1,h2, hi, w, Lmiddle, Lp, and the like) can be reference to a dimension ofa single particle of a batch. Alternatively, any reference to any of thedimensional characteristics can refer to a median value or an averagevalue derived from analysis of a suitable sampling of particles from abatch. Unless stated explicitly, reference herein to a dimensionalcharacteristic can be considered reference to a median value that is abased on a statistically significant value derived from a sample size ofsuitable number of particles of a batch. Notably, for certainembodiments herein, the sample size can include at least 40 randomlyselected particles from a batch of particles. A batch of particles maybe a group of particles that are collected from a single process run,and more particularly, may include an amount of shaped abrasiveparticles suitable for forming a commercial grade abrasive product, suchas at least about 20 lbs. of particles.

In accordance with an embodiment, the body 801 of the shaped abrasiveparticle can have a first corner height (hc) at a first region of thebody defined by a corner 813. Notably, the corner 813 may represent thepoint of greatest height on the body 801, however, the height at thecorner 813 does not necessarily represent the point of greatest heighton the body 801. The corner 813 can be defined as a point or region onthe body 301 defined by the joining of the upper surface 803, and twoside surfaces 805 and 807. The body 801 may further include othercorners, spaced apart from each other, including for example, corner 811and corner 812. As further illustrated, the body 801 can include edges814, 815, and 816 that can separated from each other by the corners 811,812, and 813. The edge 814 can be defined by an intersection of theupper surface 803 with the side surface 806. The edge 815 can be definedby an intersection of the upper surface 803 and side surface 805 betweencorners 811 and 813. The edge 816 can be defined by an intersection ofthe upper surface 803 and side surface 807 between corners 812 and 813.

As further illustrated, the body 801 can include a second midpointheight (hm) at a second end of the body 801, which can be defined by aregion at the midpoint of the edge 814, which can be opposite the firstend defined by the corner 813. The axis 850 can extend between the twoends of the body 801. FIG. 8B is a cross-sectional illustration of thebody 801 along the axis 850, which can extend through a midpoint 881 ofthe body 801 along the dimension of length (Lmiddle) between the corner813 and the midpoint of the edge 814.

In accordance with an embodiment, the shaped abrasive particles of theembodiments herein, including for example, the particle of FIGS. 8A and8B can have an average difference in height, which is a measure of thedifference between he and hm. For convention herein, average differencein height will be generally identified as hc-hm, however it is definedan absolute value of the difference and it will be appreciated thataverage difference in height may be calculated as hm-hc when the heightof the body 801 at the midpoint of the edge 814 is greater than theheight at the corner 813. More particularly, the average difference inheight can be calculated based upon a plurality of shaped abrasiveparticles from a suitable sample size, such as at least 40 particlesfrom a batch as defined herein. The heights he and hm of the particlescan be measured using a STIL (Sciences et Techniques Industrielles de laLumiere—France) Micro Measure 3D Surface Profilometer (white light (LED)chromatic aberration technique) and the average difference in height canbe calculated based on the average values of he and hm from the sample.

As illustrated in FIG. 8B, in one particular embodiment, the body 801 ofthe shaped abrasive particle may have an average difference in height atdifferent locations at the body. The body can have an average differencein height, which can be the absolute value of [hc−hm] between the firstcorner height (hc) and the second midpoint height (hm) is at least about20 microns. It will be appreciated that average difference in height maybe calculated as hm−hc when the height of the body 801 at a midpoint ofthe edge is greater than the height at an opposite corner. In otherinstances, the average difference in height [hc−hm], can be at leastabout 25 microns, at least about 30 microns, at least about 36 microns,at least about 40 microns, at least about 60 microns, such as at leastabout 65 microns, at least about 70 microns, at least about 75 microns,at least about 80 microns, at least about 90 microns, or even at leastabout 100 microns. In one non-limiting embodiment, the averagedifference in height can be not greater than about 300 microns, such asnot greater than about 250 microns, not greater than about 220 microns,or even not greater than about 180 microns. It will be appreciated thatthe average difference in height can be within a range between any ofthe minimum and maximum values noted above.

Moreover, it will be appreciated that the average difference in heightcan be based upon an average value of hc. For example, the averageheight of the body at the corners (Ahc) can be calculated by measuringthe height of the body at all corners and averaging the values, and maybe distinct from a single value of height at one corner (hc).Accordingly, the average difference in height may be given by theabsolute value of the equation [Ahc−hi], wherein hi is the interiorheight which can be the smallest dimension of height of the body asmeasured along a dimension between any corner and opposite midpoint edgeon the body. Furthermore, it will be appreciated that the averagedifference in height can be calculated using a median interior height(Mhi) calculated from a suitable sample size of a batch of shapedabrasive particles and an average height at the corners for allparticles in the sample size. Accordingly, the average difference inheight may be given by the absolute value of the equation [Ahc−Mhi].

In particular instances, the body 801 can be formed to have a primaryaspect ratio, which is a ratio expressed as width:length, wherein thelength may be Lmidddle, having a value of at least 1:1. In otherinstances, the body can be formed such that the primary aspect ratio(w:l) is at least about 1.5:1, such as at least about 2:1, at leastabout 4:1, or even at least about 5:1. Still, in other instances, theabrasive particle can be formed such that the body has a primary aspectratio that is not greater than about 10:1, such as not greater than 9:1,not greater than about 8:1, or even not greater than about 5:1. It willbe appreciated that the body 801 can have a primary aspect ratio withina range between any of the ratios noted above. Furthermore, it will beappreciated that reference herein to a height is the maximum heightmeasurable of the abrasive particle. It will be described later that theabrasive particle may have different heights at different positionswithin the body 801.

In addition to the primary aspect ratio, the abrasive particle can beformed such that the body 801 comprises a secondary aspect ratio, whichcan be defined as a ratio of length:height, wherein the length may beLmiddle and the height is an interior height (hi). In certain instances,the secondary aspect ratio can be within a range between about 5:1 andabout 1:3, such as between about 4:1 and about 1:2, or even betweenabout 3:1 and about 1:2. It will be appreciated that the same ratio maybe measured using median values (e.g., median length and interior medianheight) for a batch of particles.

In accordance with another embodiment, the abrasive particle can beformed such that the body 801 comprises a tertiary aspect ratio, definedby the ratio width:height, wherein the height is an interior height(hi). The tertiary aspect ratio of the body 801 can be within a rangebetween about 10:1 and about 1.5:1, such as between 8:1 and about 1.5:1,such as between about 6:1 and about 1.5:1, or even between about 4:1 andabout 1.5:1. It will be appreciated that the same ratio may be measuredusing median values (e.g., median length, median middle length, and/orinterior median height) for a batch of particles.

According to one embodiment, the body 801 of the shaped abrasiveparticle can have particular dimensions, which may facilitate improvedperformance. For example, in one instance, the body can have an interiorheight (hi), which can be the smallest dimension of height of the bodyas measured along a dimension between any corner and opposite midpointedge on the body. In particular instances, wherein the body is agenerally triangular two-dimensional shape, the interior height (hi) maybe the smallest dimension of height (i.e., measure between the bottomsurface 804 and the upper surface 805) of the body for threemeasurements taken between each of the three corners and the oppositemidpoint edges. The interior height (hi) of the body of a shapedabrasive particle is illustrated in FIG. 8B. According to oneembodiment, the interior height (hi) can be at least about 28% of thewidth (w). The height (hi) of any particle may be measured by sectioningor mounting and grinding the shaped abrasive particle and viewing in amanner sufficient (e.g., light microscope or SEM) to determine thesmallest height (hi) within the interior of the body 801. In oneparticular embodiment, the height (hi) can be at least about 29% of thewidth, such as at least about 30%, or even at least about 33% of thewidth of the body. For one non-limiting embodiment, the height (hi) ofthe body can be not greater than about 80% of the width, such as notgreater than about 76%, not greater than about 73%, not greater thanabout 70%, not greater than about 68% of the width, not greater thanabout 56% of the width, not greater than about 48% of the width, or evennot greater than about 40% of the width. It will be appreciated that theheight (hi) of the body can be within a range between any of the abovenoted minimum and maximum percentages.

A batch of shaped abrasive particles can be fabricated, wherein themedian interior height value (Mhi) can be controlled, which mayfacilitate improved performance. In particular, the median internalheight (hi) of a batch can be related to a median width of the shapedabrasive particles of the batch in the same manner as described above.Notably, the median interior height (Mhi) can be at least about 28%,such as at least about 29%, at least about 30%, or even at least about33% of the median width of the shaped abrasive particles of the batch.For one non-limiting embodiment, the median interior height (Mhi) of thebody can be not greater than about 80%, such as not greater than about76%, not greater than about 73%, not greater than about 70%, not greaterthan about 68% of the width, not greater than about 56% of the width,not greater than about 48% of the width, or even not greater than about40% of the median width. It will be appreciated that the median interiorheight (Mhi) of the body can be within a range between any of the abovenoted minimum and maximum percentages.

Furthermore, the batch of shaped abrasive particles may exhibit improveddimensional uniformity as measured by the standard deviation of adimensional characteristic from a suitable sample size. According to oneembodiment, the shaped abrasive particles can have an interior heightvariation (Vhi), which can be calculated as the standard deviation ofinterior height (hi) for a suitable sample size of particles from abatch. According to one embodiment, the interior height variation can benot greater than about 60 microns, such as not greater than about 58microns, not greater than about 56 microns, or even not greater thanabout 54 microns. In one non-limiting embodiment, the interior heightvariation (Vhi) can be at least about 2 microns. It will be appreciatedthat the interior height variation of the body can be within a rangebetween any of the above noted minimum and maximum values.

For another embodiment, the body of the shaped abrasive particle canhave an interior height (hi) of at least about 400 microns. Moreparticularly, the height may be at least about 450 microns, such as atleast about 475 microns, or even at least about 500 microns. In stillone non-limiting embodiment, the height of the body can be not greaterthan about 3 mm, such as not greater than about 2 mm, not greater thanabout 1.5 mm, not greater than about 1 mm, not greater than about 800microns. It will be appreciated that the height of the body can bewithin a range between any of the above noted minimum and maximumvalues. Moreover, it will be appreciated that the above range of valuescan be representative of a median interior height (Mhi) value for abatch of shaped abrasive particles.

For certain embodiments herein, the body of the shaped abrasive particlecan have particular dimensions, including for example, a width≧length, alength≧height, and a width≧height. More particularly, the body 801 ofthe shaped abrasive particle can have a width (w) of at least about 600microns, such as at least about 700 microns, at least about 800 microns,or even at least about 900 microns. In one non-limiting instance, thebody can have a width of not greater than about 4 mm, such as notgreater than about 3 mm, not greater than about 2.5 mm, or even notgreater than about 2 mm. It will be appreciated that the width of thebody can be within a range between any of the above noted minimum andmaximum values. Moreover, it will be appreciated that the above range ofvalues can be representative of a median width (Mw) for a batch ofshaped abrasive particles.

The body 801 of the shaped abrasive particle can have particulardimensions, including for example, a length (L middle or Lp) of at leastabout 0.4 mm, such as at least about 0.6 mm, at least about 0.8 mm, oreven at least about 0.9 mm. Still, for at least one non-limitingembodiment, the body 801 can have a length of not greater than about 4mm, such as not greater than about 3 mm, not greater than about 2.5 mm,or even not greater than about 2 mm. It will be appreciated that thelength of the body 801 can be within a range between any of the abovenoted minimum and maximum values. Moreover, it will be appreciated thatthe above range of values can be representative of a median length (Ml),which may be more particularly, a median middle length (MLmiddle) ormedian profile length (MLp) for a batch of shaped abrasive particles.The shaped abrasive particle can have a body 801 having a particularamount of dishing, wherein the dishing value (d) can be defined as aratio between an average height of the body 801 at the corners (Ahc) ascompared to smallest dimension of height of the body at the interior(hi). The average height of the body 801 at the corners (Ahc) can becalculated by measuring the height of the body at all corners andaveraging the values, and may be distinct from a single value of heightat one corner (hc). The average height of the body 801 at the corners orat the interior can be measured using a STIL (Sciences et TechniquesIndustrielles de la Lumiere—France) Micro Measure 3D SurfaceProfilometer (white light (LED) chromatic aberration technique).Alternatively, the dishing may be based upon a median height of theparticles at the corner (Mhc) calculated from a suitable sampling ofparticles from a batch. Likewise, the interior height (hi) can be amedian interior height (Mhi) derived from a suitable sampling of shapedabrasive particles from a batch. According to one embodiment, thedishing value (d) can be not greater than about 2, such as not greaterthan about 1.9, not greater than about 1.8, not greater than about 1.7,not greater than about 1.6, or even not greater than about 1.5. Still,in at least one non-limiting embodiment, the dishing value (d) can be atleast about 0.9, such as at least about 1.0. It will be appreciated thatthe dishing ratio can be within a range between any of the minimum andmaximum values noted above. Moreover, it will be appreciated that theabove dishing values can be representative of a median dishing value(Md) for a batch of shaped abrasive particles.

The shaped abrasive particles of the embodiments herein, including forexample, the body 801 of the particle of FIG. 8A can have a bottomsurface 804 defining a bottom area (A_(b)). In particular instances thebottom surface 304 can be the largest surface of the body 801. Thebottom surface can have a surface area defined as the bottom area(A_(b)) that is greater than the surface area of the upper surface 803.Additionally, the body 801 can have a cross-sectional midpoint area(A_(m)) defining an area of a plane perpendicular to the bottom area andextending through a midpoint 881 (a between the top and bottom surfaces)of the particle. In certain instances, the body 801 can have an arearatio of bottom area to midpoint area (A_(b)/A_(m)) of not greater thanabout 6. In more particular instances, the area ratio can be not greaterthan about 5.5, such as not greater than about 5, not greater than about4.5, not greater than about 4, not greater than about 3.5, or even notgreater than about 3. Still, in one non-limiting embodiment, the arearatio may be at least about 1.1, such as at least about 1.3, or even atleast about 1.8. It will be appreciated that the area ratio can bewithin a range between any of the minimum and maximum values notedabove. Moreover, it will be appreciated that the above area ratios canbe representative of a median area ratio for a batch of shaped abrasiveparticles.

Furthermore the shaped abrasive particles of the embodiments herein,including for example, the particle of FIG. 8B can have a normalizedheight difference of at least about 0.3. The normalized heightdifference can be defined by the absolute value of the equation[(hc−hm)/(hi)]. In other embodiments, the normalized height differencecan be not greater than about 0.26, such as not greater than about 0.22,or even not greater than about 0.19. Still, in one particularembodiment, the normalized height difference can be at least about 0.04,such as at least about 0.05, at least about 0.06. It will be appreciatedthat the normalized height difference can be within a range between anyof the minimum and maximum values noted above. Moreover, it will beappreciated that the above normalized height values can berepresentative of a median normalized height value for a batch of shapedabrasive particles.

In another instance, the body 801 can have a profile ratio of at leastabout 0.04, wherein the profile ratio is defined as a ratio of theaverage difference in height [hc-hm] to the length (Lmiddle) of theshaped abrasive particle, defined as the absolute value of[(hc-hm)/(Lmiddle)]. It will be appreciated that the length (Lmiddle) ofthe body can be the distance across the body 801 as illustrated in FIG.8B. Moreover, the length may be an average or median length calculatedfrom a suitable sampling of particles from a batch of shaped abrasiveparticles as defined herein. According to a particular embodiment, theprofile ratio can be at least about 0.05, at least about 0.06, at leastabout 0.07, at least about 0.08, or even at least about 0.09. Still, inone non-limiting embodiment, the profile ratio can be not greater thanabout 0.3, such as not greater than about 0.2, not greater than about0.18, not greater than about 0.16, or even not greater than about 0.14.It will be appreciated that the profile ratio can be within a rangebetween any of the minimum and maximum values noted above. Moreover, itwill be appreciated that the above profile ratio can be representativeof a median profile ratio for a batch of shaped abrasive particles.

According to another embodiment, the body 801 can have a particular rakeangle, which may be defined as an angle between the bottom surface 804and a side surface 805, 806 or 807 of the body. For example, the rakeangle may be within a range between about 1 and about 80°. For otherparticles herein, the rake angle can be within a range between about 5°and 55°, such as between about 10° and about 50°, between about 15° and50°, or even between about 20° and 50°. Formation of an abrasiveparticle having such a rake angle can improve the abrading capabilitiesof the abrasive particle. Notably, the rake angle can be within a rangebetween any two rake angles noted above.

According to another embodiment, the shaped abrasive particles herein,including for example the particles of FIGS. 8A and 8B can have anellipsoidal region 817 in the upper surface 803 of the body 801. Theellipsoidal region 817 can be defined by a trench region 818 that canextend around the upper surface 803 and define the ellipsoidal region817. The ellipsoidal region 817 can encompass the midpoint 881.Moreover, it is thought that the ellipsoidal region 817 defined in theupper surface can be an artifact of the forming process, and may beformed as a result of the stresses imposed on the mixture duringformation of the shaped abrasive particles according to the methodsdescribed herein.

The shaped abrasive particle can be formed such that the body includes acrystalline material, and more particularly, a polycrystalline material.Notably, the polycrystalline material can include abrasive grains. Inone embodiment, the body can be essentially free of an organic material,including for example, a binder. More particularly, the body can consistessentially of a polycrystalline material.

In one aspect, the body of the shaped abrasive particle can be anagglomerate including a plurality of abrasive particles, grit, and/orgrains bonded to each other to form the body 801 of the abrasiveparticle 800. Suitable abrasive grains can include nitrides, oxides,carbides, borides, oxynitrides, oxyborides, diamond, superabrasives(e.g., cBN) and a combination thereof. In particular instances, theabrasive grains can include an oxide compound or complex, such asaluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, chromiumoxide, strontium oxide, silicon oxide, and a combination thereof. In oneparticular instance, the abrasive particle 800 is formed such that theabrasive grains forming the body 800 include alumina, and moreparticularly, may consist essentially of alumina. In an alternativeembodiment, the shaped abrasive particles can include geosets, includingfor example, polycrystalline compacts of abrasive or superabrasivematerials including a binder phase, which may include a metal, metalalloy, super alloy, cermet, and a combination thereof. Some exemplarybinder materials can include cobalt, tungsten, and a combinationthereof.

The abrasive grains (i.e., crystallites) contained within the body mayhave an average grain size that is generally not greater than about 100microns. In other embodiments, the average grain size can be less, suchas not greater than about 80 microns, not greater than about 50 microns,not greater than about 30 microns, not greater than about 20 microns,not greater than about 10 microns, or even not greater than about 1micron. Still, the average grain size of the abrasive grains containedwithin the body can be at least about 0.01 microns, such as at leastabout 0.05 microns, such as at least about 0.08 microns, at least about0.1 microns, or even at least about 1 micron. It will be appreciatedthat the abrasive grains can have an average grain size within a rangebetween any of the minimum and maximum values noted above.

In accordance with certain embodiments, the abrasive particle can be acomposite article including at least two different types of abrasivegrains within the body. It will be appreciated that different types ofabrasive grains are abrasive grains having different compositions withregard to each other. For example, the body can be formed such that isincludes at least two different types of abrasive grains, wherein thetwo different types of abrasive grains can be nitrides, oxides,carbides, borides, oxynitrides, oxyborides, diamond, and a combinationthereof.

In accordance with an embodiment, the abrasive particle 800 can have anaverage particle size, as measured by the largest dimension measurableon the body 801, of at least about 100 microns. In fact, the abrasiveparticle 800 can have an average particle size of at least about 150microns, such as at least about 200 microns, at least about 300 microns,at least about 400 microns, at least about 500 microns, at least about600 microns, at least about 700 microns, at least about 800 microns, oreven at least about 900 microns. Still, the abrasive particle 800 canhave an average particle size that is not greater than about 5 mm, suchas not greater than about 3 mm, not greater than about 2 mm, or even notgreater than about 1.5 mm. It will be appreciated that the abrasiveparticle 100 can have an average particle size within a range betweenany of the minimum and maximum values noted above.

The shaped abrasive particles of the embodiments herein can have apercent flashing that may facilitate improved performance. Notably, theflashing defines an area of the particle as viewed along one side, suchas illustrated in FIG. 8C, wherein the flashing extends from a sidesurface of the body within the boxes 888 and 889. The flashing canrepresent tapered regions proximate to the upper surface and bottomsurface of the body. The flashing can be measured as the percentage ofarea of the body along the side surface contained within a box extendingbetween an innermost point of the side surface (e.g., 891) and anoutermost point (e.g., 892) on the side surface of the body. In oneparticular instance, the body can have a particular content of flashing,which can be the percentage of area of the body contained within theboxes 888 and 889 compared to the total area of the body containedwithin boxes 888, 889, and 890. According to one embodiment, the percentflashing (f) of the body can be at least about 10%. In anotherembodiment, the percent flashing can be greater, such as at least about12%, such as at least about 14%, at least about 16%, at least about 18%,or even at least about 20%. Still, in a non-limiting embodiment, thepercent flashing of the body can be controlled and may be not greaterthan about 45%, such as not greater than about 40%, or even not greaterthan about 36%. It will be appreciated that the percent flashing of thebody can be within a range between any of the above minimum and maximumpercentages. Moreover, it will be appreciated that the above flashingpercentages can be representative of an average flashing percentage or amedian flashing percentage for a batch of shaped abrasive particles.

The percent flashing can be measured by mounting the shaped abrasiveparticle on its side and viewing the body at the side to generate ablack and white image, such as illustrated in FIG. 8C. A suitableprogram for creating and analyzing images including the calculation ofthe flashing can be ImageJ software. The percentage flashing can becalculated by determining the area of the body 801 in the boxes 888 and889 compared to the total area of the body as viewed at the side (totalshaded area), including the area in the center 890 and within the boxes888 and 889. Such a procedure can be completed for a suitable samplingof particles to generate average, median, and/or and standard deviationvalues.

A batch of shaped abrasive particles according to embodiments herein mayexhibit improved dimensional uniformity as measured by the standarddeviation of a dimensional characteristic from a suitable sample size.According to one embodiment, the shaped abrasive particles can have aflashing variation (Vf), which can be calculated as the standarddeviation of flashing percentage (f) for a suitable sample size ofparticles from a batch. According to one embodiment, the flashingvariation can be not greater than about 5.5%, such as not greater thanabout 5.3%, not greater than about 5%, or not greater than about 4.8%,not greater than about 4.6%, or even not greater than about 4.4%. In onenon-limiting embodiment, the flashing variation (Vf) can be at leastabout 0.1%. It will be appreciated that the flashing variation can bewithin a range between any of the minimum and maximum percentages notedabove.

The shaped abrasive particles of the embodiments herein can have aheight (hi) and flashing multiplier value (hiF) of at least 4000,wherein hiF=(hiXf), an “hi” represents a minimum interior height of thebody as described above and “f” represents the percent flashing. In oneparticular instance, the height and flashing multiplier value (hiF) ofthe body can be greater, such as at least about 4500 micron %, at leastabout 5000 micron %, at least about 6000 micron %, at least about 7000micron %, or even at least about 8000 micron %. Still, in onenon-limiting embodiment, the height and flashing multiplier value can benot greater than about 45000 micron %, such as not greater than about30000 micron %, not greater than about 25000 micron %, not greater thanabout 20000 micron %, or even not greater than about 18000 micron %. Itwill be appreciated that the height and flashing multiplier value of thebody can be within a range between any of the above minimum and maximumvalues. Moreover, it will be appreciated that the above multiplier valuecan be representative of a median multiplier value (MhiF) for a batch ofshaped abrasive particles.

The shaped abrasive particles of the embodiments herein can have adishing (d) and flashing (F) multiplier value (dF) as calculated by theequation dF=(dXF), wherein dF is not greater than about 90%, “d”represents the dishing value, and “f” represents the percentage flashingof the body. In one particular instance, the dishing (d) and flashing(F) multiplier value (dF) of the body can be not greater than about 70%,such as not greater than about 60%, not greater than about 55%, notgreater than about 48%, not greater than about 46%. Still, in onenon-limiting embodiment, the dishing (d) and flashing (F) multipliervalue (dF) can be at least about 10%, such as at least about 15%, atleast about 20%, at least about 22%, at least about 24%, or even atleast about 26%. It will be appreciated that the dishing (d) andflashing (F) multiplier value (dF) of the body can be within a rangebetween any of the above minimum and maximum values. Moreover, it willbe appreciated that the above multiplier value can be representative ofa median multiplier value (MdF) for a batch of shaped abrasiveparticles.

The shaped abrasive particles of the embodiments herein can have aheight and dishing ratio (hi/d) as calculated by the equationhi/d=(hi)/(d), wherein hi/d is not greater than about 1000, “hi”represents a minimum interior height as described above, and “d”represents the dishing of the body. In one particular instance, theratio (hi/d) of the body can be not greater than about 900 microns, notgreater than about 800 microns, not greater than about 700 microns, oreven not greater than about 650 microns. Still, in one non-limitingembodiment, the ratio (hi/d), can be at least about 10 microns, such asat least about 50 microns, at least about 100 microns, at least about150 microns, at least about 200 microns, at least about 250 microns, oreven at least about 275 microns. It will be appreciated that the ratio(hi/d) of the body can be within a range between any of the aboveminimum and maximum values. Moreover, it will be appreciated that theabove height and dishing ratio can be representative of a median heightand dishing ratio (Mhi/d) for a batch of shaped abrasive particles.

Abrasive Articles

FIG. 1A includes a top view illustration of a portion of an abrasivearticle according to an embodiment. As illustrated, the abrasive article100 can include a backing 101. The backing 101 can include an organicmaterial, inorganic material, and a combination thereof. In certaininstances, the backing 101 can include a woven material. However, thebacking 101 may be made of a non-woven material. Particularly suitablebacking materials can include organic materials, including polymers, andparticularly, polyester, polyurethane, polypropylene, polyimides such asKAPTON from DuPont, and paper. Some suitable inorganic materials caninclude metals, metal alloys, and particularly, foils of copper,aluminum, steel, and a combination thereof. It will be appreciated thatthe abrasive article 100 can include other components, including forexample adhesive layers (e.g. make coat, size coat, front fill, etc.),which will be discussed in more detail herein.

As further illustrated, the abrasive article 100 can include a shapedabrasive particle 102 overlying the backing 101, and more particularly,coupled to the backing 101. Notably, the shaped abrasive particle 102can be placed at a first, predetermined position 112 on the backing 101.As further illustrated, the abrasive article 100 can further include ashaped abrasive particle 103 that may be overlying the backing 101, andmore particularly, coupled to the backing 101 in a second, predeterminedposition 113. The abrasive article 100 can further include a shapedabrasive particle 104 overlying the backing 101, and more particularly,coupled to the backing 101 in a third, predetermined position 114. Asfurther illustrated in FIG. 1A, the abrasive article 100 can furtherinclude a shaped abrasive particle 105 overlying the backing 101, andmore particularly, coupled to the backing 101 in a fourth, predeterminedposition 115. As further illustrated, the abrasive article 100 caninclude a shaped abrasive particle overlying the backing 101, and moreparticularly, coupled to the backing 101 in a fifth, predeterminedposition 116. It will be appreciated that any of the shaped abrasiveparticles described herein may be coupled to the backing 101 via one ormore adhesive layers as described herein.

In accordance with an embodiment, the shaped abrasive particle 102 canhave a first composition. For example, the first composition can includea crystalline material. In one particular embodiment, the firstcomposition can include a ceramic material, such as an oxide, carbide,nitride, boride, oxynitride, oxycarbide, and a combination thereof. Moreparticularly, the first composition may consist essentially of aceramic, such that it may consist essentially of an oxide, carbide,nitride, boride, oxynitride, oxycarbide, and a combination thereof.Still, in an alternative embodiment, the first composition can include asuperabrasive material. Still in other embodiments, the firstcomposition can include a single phase material, and more particularlymay consist essentially of a single phase material. Notably, the firstcomposition may be a single phase polycrystalline material. In specificinstances, the first composition may have limited binder content, suchthat the first composition may have not greater than about 1% bindermaterial. Some suitable exemplary binders materials can include organicmaterials, and more particularly, polymer containing compounds. Morenotably, the first composition may be essentially free of bindermaterial and may be essentially free of an organic material. Inaccordance with one embodiment, the first composition can includealumina, and more particularly, may consist essentially of alumina, suchas alpha alumina.

Still, in yet another aspect, the shaped abrasive particle 102 can havea first composition that can be a composite including at least twodifferent types of abrasive grains within the body.

It will be appreciated that different types of abrasive grains areabrasive grains having different compositions with regard to each other.For example, the body can be formed such that is includes at least twodifferent types of abrasive grains, wherein the two different types ofabrasive grains can be nitrides, oxides, carbides, borides, oxynitrides,oxyborides, diamond, and a combination thereof.

In one embodiment, the first composition may include a dopant material,wherein the dopant material is present in a minor amount. Some suitableexemplary dopant materials can include an element or compound such as analkali element, alkaline earth element, rare earth element, hafnium,zirconium, niobium, tantalum, molybdenum, vanadium, or a combinationthereof. In one particular embodiment, the dopant material includes anelement or compound including an element such as lithium, sodium,potassium, magnesium, calcium, strontium, barium, scandium, yttrium,lanthanum, cesium, praseodymium, niobium, hafnium, zirconium, tantalum,molybdenum, vanadium, chromium, cobalt, iron, germanium, manganese,nickel, titanium, zinc, and a combination thereof.

The second shaped abrasive particle 103 may have a second composition.In certain instances, the second composition of the second shapedabrasive particle 103 may be substantially the same as the firstcomposition of the first shaped abrasive particle 102. Moreparticularly, the second composition may be essentially the same as thefirst composition. Still, in an alternative embodiment, the secondcomposition of the second shaped abrasive particle 103 may besignificantly different that the first composition of the first shapedabrasive particle 102. It will be appreciated that the secondcomposition can include any of the materials, elements, and compoundsdescribed in accordance with the first composition.

In accordance with an embodiment, and as further illustrated in FIG. 1A,the first shaped abrasive particle 102 and second shaped abrasiveparticle 103 may be arranged in a predetermined distribution relative toeach other.

A predetermined distribution can be defined by a combination ofpredetermined positions on a backing that are purposefully selected. Apredetermined distribution can include a pattern, such that thepredetermined positions can define a two-dimensional array. An array caninclude have short range order defined by a unit of shaped abrasiveparticles. An array may also be a pattern, having long range orderincluding regular and repetitive units linked together, such that thearrangement may be symmetrical and/or predictable. An array may have anorder that can be predicted by a mathematical formula. It will beappreciated that two-dimensional arrays can be formed in the shape ofpolygons, ellipsis, ornamental indicia, product indicia, or otherdesigns.

A predetermined distribution can also include a non-shadowingarrangement. A non-shadowing arrangement may include a controlled,non-uniform distribution, a controlled uniform distribution, and acombination thereof. In particular instances, a non-shadowingarrangement may include a radial pattern, a spiral pattern, aphyllotactic pattern, an asymmetric pattern, a self-avoiding randomdistribution, a self-avoiding random distribution and a combinationthereof.

Non-shadowing arrangements include a particular arrangement of abrasiveparticles (i.e., shaped abrasive particles and/or diluent particles)relative to each other, wherein the degree of overlap of the abrasiveparticles during an initial phase of a material removal operation is notgreater than about 25%, such as not greater than about 20%, not greaterthan about 15%, not greater than about 10%, or even not greater thanabout 5%. In particular instances, a non-shadowing arrangement mayinclude a distribution of abrasive particles, wherein upon engagementwith a workpiece during an initial stage of a material removaloperation, a portion (e.g., a minority of all shaped abrasive particleson the backing, a majority of all shaped abrasive particles on thebacking, or even essentially all) of the abrasive particles engage adifferent region of the surface of the workpiece. A non-shadowingarrangement may utilize a particular distribution of shaped abrasiveparticles relative to each other and relative to a grinding direction asdescribed in embodiments herein. Utilization of an abrasive articleemploying a non-shadowing arrangement of abrasive particles canfacilitate improved grinding performance over other abrasive articlesusing conventional patterned arrangements (i.e., shadowed arrangement)and may limit other undesirable effects, such as steering of theabrasive article during operation.

The predetermined distribution can be partially, substantially, or fullyasymmetric. The predetermined distribution can overlie the entireabrasive article, can cover substantially the entire abrasive article(i.e. greater than 50% but less than 100%), overlie multiple portions ofthe abrasive article, or overlie a fraction of the abrasive article(i.e., less than 50% of the surface area of the article). As usedherein, “a phyllotactic pattern” means a pattern related to phyllotaxis.Phyllotaxis is the arrangement of lateral organs such as leaves,flowers, scales, florets, and seeds in many kinds of plants. Manyphyllotactic patterns are marked by the naturally occurring phenomenonof conspicuous patterns having arcs, spirals, and whorls. The pattern ofseeds in the head of a sunflower is an example of this phenomenon.

Furthermore, according to one embodiment, a non-shadowing arrangementcan include a microunit, which may be defined as a smallest arrangementof shaped abrasive particles relative to each other. The microunit mayrepeat a plurality of times across at least a portion of the surface ofthe abrasive article. A non-shadowing arrangement may further include amacrounit, which can include a plurality of microunits. In particularinstances, the macrounit may have a plurality of microunits arranged ina predetermined distribution relative to each other and repeating aplurality of times with the non-shadowing arrangement. Abrasive articlesof the embodiments herein can include one or more microunits.Furthermore, it will be appreciated that the abrasive articles of theembodiments herein can include one or more macrounits. In certainembodiments, the macrounits may be arranged in a uniform distributionhaving a predictable order. Still, in other instances, the macrounitsmay be arranged in a non-uniform distribution, which may include arandom distribution, having no predictable long range or short rangeorder.

Referring briefly to FIGS. 25-27, different non-shadowing arrangementsare illustrated. In particular, FIG. 25 includes an illustration of anon-shadowing arrangement, wherein the locations 2501 representpredetermined positions to be occupied by one or more shaped abrasiveparticles, diluent particles, and a combination thereof. The locations2501 may be defined as positions on X and Y axes as illustrated.Moreover, the locations 2506 and 2507 can define a microunit 2520.Furthermore, 2506 and 2509 may define a microunit 2521. As furtherillustrated, the microunits may be repeated across the surface of atleast a portion of the article and define a macrounit 2530. In oneparticular instance, the locations 2501 representing the positions ofshaped abrasive particles are arranged in a non-shadowing arrangementrelative to a grinding direction that is parallel to the Y-axis.

FIG. 26 includes an illustration of a non-shadowing arrangement, whereinthe locations (shown as dots on the X and Y axes) representpredetermined positions to be occupied by one or more shaped abrasiveparticles, diluent particles, and a combination thereof. In oneembodiment, the locations 2601 and 2602 can define a microunit 2620.Furthermore, locations 2603, 2604, and 2605 can define a microunit 2621.As further illustrated, the microunits may be repeated across thesurface of at least a portion of the article and define at least onemacrounit 2630. It will be appreciated, as illustrated, other macrounitsmay exist. In one particular instance, the locations 2601 representingthe positions of shaped abrasive particles are arranged in anon-shadowing arrangement relative to a grinding direction that isparallel to the Y-axis or X-axis.

FIG. 27 includes an illustration of a non-shadowing arrangement, whereinthe locations (shown as dots on the X and Y axes) representpredetermined positions to be occupied by one or more shaped abrasiveparticles, diluent particles, and a combination thereof. In oneembodiment, the locations 2701 and 2702 can define a microunit 2720.Furthermore, locations 2701 and 2703 can define a microunit 2721. Asfurther illustrated, the microunits may be repeated across the surfaceof at least a portion of the article and define at least one macrounit2730. In one particular instance, all of the locations that representpositions of shaped abrasive particles are arranged in a non-shadowingarrangement relative to a grinding direction that is parallel to theY-axis or X-axis.

A predetermined distribution between shaped abrasive particles can alsobe defined by at least one of a predetermined orientation characteristicof each of the shaped abrasive particles. Exemplary predeterminedorientation characteristics can include a predetermined rotationalorientation, a predetermined lateral orientation, a predeterminedlongitudinal orientation, a predetermined vertical orientation, apredetermined tip height, and a combination thereof. The backing 101 canbe defined by a longitudinal axis 180 that extends along and defines alength of the backing 101 and a lateral axis 181 that extends along anddefines a width of a backing 101.

In accordance with an embodiment, the shaped abrasive particle 102 canbe located in a first, predetermined position 112 defined by aparticular first lateral position relative to the lateral axis of 181 ofthe backing 101. Furthermore, the shaped abrasive particle 103 may havea second, predetermined position defined by a second lateral positionrelative to the lateral axis 181 of the backing 101. Notably, the shapedabrasive particles 102 and 103 may be spaced apart from each other by alateral space 121, defined as a smallest distance between the twoadjacent shaped abrasive particles 102 and 103 as measured along alateral plane 184 parallel to the lateral axis 181 of the backing 101.In accordance with an embodiment, the lateral space 121 can be greaterthan 0, such that some distance exists between the shaped abrasiveparticles 102 and 103. However, while not illustrated, it will beappreciated that the lateral space 121 can be 0, allowing for contactand even overlap between portions of adjacent shaped abrasive particle.

In other embodiments, the lateral space 121 can be at least about 0.1(w), wherein w represents the width of the shaped abrasive particle 102.According to an embodiment, the width of the shaped abrasive particle isthe longest dimension of the body extending along a side. In anotherembodiment, the lateral space 121 can be at least about 0.2(w), such asat least about 0.5(w), at least about 1(w), at least about 2(w), or evengreater. Still, in at least one non-limiting embodiment, the lateralspace 121 can be not greater than about 100(w), not greater than about50(w), or even not greater than about 20(w). It will be appreciated thatthe lateral space 121 can be within a range between any of the minimumand maximum values noted above. Control of the lateral space betweenadjacent shaped abrasive particles may facilitate improved grindingperformance of the abrasive article.

In accordance with an embodiment, the shaped abrasive particle 102 canbe in a first, predetermined position 112 defined by a firstlongitudinal position relative to a longitudinal axis 180 of the backing101. Furthermore, the shaped abrasive particle 104 may be located at athird, predetermined position 114 defined by a second longitudinalposition relative to the longitudinal axis 180 of the backing 101.Further, as illustrated, a longitudinal space 123 may exist between theshaped abrasive particles 102 and 104, which can be defined as asmallest distance between the two adjacent shaped abrasive particles 102and 104 as measured in a direction parallel to the longitudinal axis180. In accordance with an embodiment, the longitudinal space 123 can begreater than 0. Still, while not illustrated, it will be appreciatedthat the longitudinal space 123 can be 0, such that the adjacent shapedabrasive particles are touching, or even overlapping each other.

In other instances, the longitudinal space 123 can be at least about0.1(w), wherein w is the width of the shaped abrasive particle asdescribed herein. In other more particular instances, the longitudinalspace can be at least about 0.2(w), at least about 0.5(w), at leastabout 1(w), or even at least about 2(w). Still, the longitudinal space123 may be not greater than about 100(w), such as not greater than about50(w), or even not greater than about 20(w). It will be appreciated thatthe longitudinal space 123 can be within a range between any of theabove minimum and maximum values. Control of the longitudinal spacebetween adjacent shaped abrasive particles may facilitate improvedgrinding performance of the abrasive article.

In accordance with an embodiment, the shaped abrasive particles may beplaced in a predetermined distribution, wherein a particularrelationship exists between the lateral space 121 and longitudinal space123. For example, in one embodiment the lateral space 121 can be greaterthan the longitudinal space 123. Still, in another non-limitingembodiment, the longitudinal space 123 may be greater than the lateralspace 121. Still, in yet another embodiment, the shaped abrasiveparticles may be placed on the backing such that the lateral space 121and longitudinal space 123 are essentially the same relative to eachother. Control of the relative relationship between the longitudinalspace and lateral space may facilitate improved grinding performance.

As further illustrated, a longitudinal space 124 may exist between theshaped abrasive particles 104 and 105. Moreover, the predetermineddistribution may be formed such that a particular relationship can existbetween the longitudinal space 123 and longitudinal space 124. Forexample, the longitudinal space 123 can be different than thelongitudinal space 124. Alternatively, the longitudinal space 123 can beessentially the same at the longitudinal space 124. Control of therelative difference between longitudinal spaces of different abrasiveparticles may facilitate improved grinding performance of the abrasivearticle.

Furthermore, the predetermined distribution of shaped abrasive particleson the abrasive article 100 can be such that the lateral space 121 canhave a particular relationship relative to the lateral space 122. Forexample, in one embodiment the lateral space 121 can be essentially thesame as the lateral space 122. Alternatively, the predetermineddistribution of shaped abrasive particles on the abrasive article 100can be controlled such that the lateral space 121 is different than thelateral space 122. Control of the relative difference between lateralspaces of different abrasive particles may facilitate improved grindingperformance of the abrasive article.

FIG. 1B includes a side view illustration of a portion of an abrasivearticle in accordance with an embodiment. As illustrated, the abrasivearticle 100 can include a shaped abrasive particle 102 overlying thebacking 101 and a shaped abrasive particle 104 spaced apart from theshaped abrasive particle 102 overlying the backing 101. In accordancewith an embodiment, the shaped abrasive particle 102 can be coupled tothe backing 101 via the adhesive layer 151. Furthermore oralternatively, the shaped abrasive particle 102 can be coupled to thebacking 101 via the adhesive layer 152. It will be appreciated that anyof the shaped abrasive particles described herein may be coupled to thebacking 101 via one or more adhesive layers as described herein.

In accordance with an embodiment, the abrasive article 100 can includean adhesive layer 151 overlying the backing. In accordance with oneembodiment, the adhesive layer 151 can include a make coat. The makecoat can be overlying the surface of the backing 101 and surrounding atleast a portion of the shaped abrasive particles 102 and 104. Abrasivearticles of the embodiments herein can further include an adhesive layer152 overlying the adhesive layer 151 and the backing 101 and surroundingat least a portion of the shaped abrasive particles 102 and 104. Theadhesive layer 152 may be a size coat in particular instances.

A polymer formulation may be used to form any of a variety of theadhesive layers 151 or 152 of the abrasive article, which can includebut not limited to, a frontfill, a pre-size coat, a make coat, a sizecoat, and/or a supersize coat. When used to form the frontfill, thepolymer formulation generally includes a polymer resin, fibrillatedfibers (preferably in the form of pulp), filler material, and otheroptional additives. Suitable formulations for some frontfill embodimentscan include material such as a phenolic resin, wollastonite filler,defoamer, surfactant, a fibrillated fiber, and a balance of water.Suitable polymeric resin materials include curable resins selected fromthermally curable resins including phenolic resins, urea/formaldehyderesins, phenolic/latex resins, as well as combinations of such resins.Other suitable polymeric resin materials may also include radiationcurable resins, such as those resins curable using electron beam, UVradiation, or visible light, such as epoxy resins, acrylated oligomersof acrylated epoxy resins, polyester resins, acrylated urethanes andpolyester acrylates and acrylated monomers including monoacrylated,multiacrylated monomers. The formulation can also comprise a nonreactivethermoplastic resin binder which can enhance the self-sharpeningcharacteristics of the deposited abrasive composites by enhancing theerodability. Examples of such thermoplastic resin include polypropyleneglycol, polyethylene glycol, and polyoxypropylene-polyoxyethene blockcopolymer, etc. Use of a frontfill on the backing can improve theuniformity of the surface, for suitable application of the make coat andimproved application and orientation of shaped abrasive particles in apredetermined orientation.

Either of the adhesive layers 151 and 152 can be applied to the surfaceof the backing 101 in a single process, or alternatively, the shapedabrasive particles 102 and 104 can be combined with a material of one ofthe adhesive layers 151 or 152 and applied as a mixture to the surfaceof the backing 101. Suitable materials of the adhesive layer 151 for useas a make coat can include organic materials, particularly polymericmaterials, including for example, polyesters, epoxy resins,polyurethanes, polyamides, polyacrylates, polymethacrylates, poly vinylchlorides, polyethylene, polysiloxane, silicones, cellulose acetates,nitrocellulose, natural rubber, starch, shellac, and mixtures thereof.In one embodiment, the adhesive layer 151 can include a polyester resin.The coated backing 101 can then be heated in order to cure the resin andthe abrasive particulate material to the substrate. In general, thecoated backing 101 can be heated to a temperature of between about 100°C. to less than about 250° C. during this curing process.

The adhesive layer 152 may be formed on the abrasive article, which maybe in the form of a size coat. In accordance with a particularembodiment, the adhesive layer 152 can be a size coat formed to overlieand bond the shaped abrasive particles 102 and 104 in place relative tothe backing 101. The adhesive layer 152 can include an organic material,may be made essentially of a polymeric material, and notably, can usepolyesters, epoxy resins, polyurethanes, polyamides, polyacrylates,polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane,silicones, cellulose acetates, nitrocellulose, natural rubber, starch,shellac, and mixtures thereof.

It will be appreciated, that while not illustrated, the abrasive articlecan include diluent abrasive particles different than the shapedabrasive particles 104 and 105. For example, the diluent particles candiffer from the shaped abrasive particles 102 and 104 in composition,two-dimensional shape, three-dimensional shape, size, and a combinationthereof. For example, the abrasive particles 507 can representconventional, crushed abrasive grit having random shapes. The abrasiveparticles 507 may have a median particle size less than the medianparticle size of the shaped abrasive particles 505.

As further illustrated, the shaped abrasive particle 102 can be orientedin a side orientation relative to the backing 101, wherein a sidesurface 171 of the shaped abrasive particle 102 can be in direct contactwith the backing 101 or at least a surface of the shaped abrasiveparticle 102 closest to the upper surface of the backing 101. Inaccordance with an embodiment, the shaped abrasive particle 102 can havea vertical orientation defined by a tilt angle (A_(T1)) 136 between amajor surface 172 of the shaped abrasive particle 102 and a majorsurface 161 of the backing 101. The tilt angle 136 can be defined as thesmallest angle or acute angle between the surface 172 of the shapedabrasive particle 102 and the upper surface 161 of the backing 101. Inaccordance with an embodiment, the shaped abrasive particle 102 can beplaced in a position having a predetermined vertical orientation. Inaccordance with an embodiment, the tilt angle 136 can be at least about2°, such as at least about 5°, at least about 10°, at least about 15°,at least about 20°, at least about 25°, at least about 30°, at leastabout 35°, at least about 40°, at least about 45°, at least about 50°,at least about 55°, at least about 60°, at least about 70°, at leastabout 80°, or even at least about 85°. Still, the tilt angle 136 may benot greater than about 90°, such as not greater than about 85°, notgreater than about 80°, not greater than about 75°, not greater thanabout 70°, not greater than about 65°, not greater than about 60°, suchas not greater than about 55°, not greater than about 50°, not greaterthan about 45°, not greater than about 40°, not greater than about 35°,not greater than about 30°, not greater than about 25°, not greater thanabout 20°, such as not greater than about 15°, not greater than about10°, or even not greater than about 5°. It will be appreciated that thetilt angle 136 can be within a range between any of the above minimumand maximum degrees.

As further illustrated, the abrasive article 100 can include a shapedabrasive particle 104 in a side orientation, wherein a side surface 171of the shaped abrasive particle 104 is in direct contact with or closestto an upper surface 161 of the backing 101. In accordance with anembodiment, the shaped abrasive particle 104 can be in a position havinga predetermined vertical orientation defined by a second tilt angle (Ar)137 defining an angle between a major surface 172 of the shaped abrasiveparticle 104 and the upper surface 161 of the backing 101.

The tilt angle 137 may be defined as the smallest angle between a majorsurface 172 of the shaped abrasive particle 104 and an upper surface 161of the backing 101. Moreover, the tilt angle 137 can have a value of atleast about 2°, such as at least about 5°, at least about 10°, at leastabout 15°, at least about 20°, at least about 25°, at least about 30°,at least about 35°, at least about 40°, at least about 45°, at leastabout 50°, at least about 55°, at least about 60°, at least about 70°,at least about 80°, or even at least about 85°. Still, the tilt angle136 may be not greater than about 90°, such as not greater than about85°, not greater than about 80°, not greater than about 75°, not greaterthan about 70°, not greater than about 65°, not greater than about 60°,such as not greater than about 55°, not greater than about 50°, notgreater than about 45°, not greater than about 40°, not greater thanabout 35°, not greater than about 30°, not greater than about 25°, notgreater than about 20°, such as not greater than about 15°, not greaterthan about 10°, or even not greater than about 5°. It will beappreciated that the tilt angle 136 can be within a range between any ofthe above minimum and maximum degrees.

In accordance with an embodiment, the shaped abrasive particle 102 canhave a predetermined vertical orientation that is the same as thepredetermined vertical orientation of the shaped abrasive particle 104.Alternatively, the abrasive article 100 may be formed such that thepredetermined vertical orientation of the shaped abrasive particle 102can be different than the predetermined vertical orientation of theshaped abrasive particle 104.

In accordance with an embodiment, the shaped abrasive particles 102 and104 may be placed on the backing such that they have differentpredetermined vertical orientations defined by a vertical orientationdifference. The vertical orientation difference can be the absolutevalue of the difference between the tilt angle 136 and the tilt angle137. In accordance with an embodiment, the vertical orientationdifference can be at least about 2, such as at least about 5°, at leastabout 10°, at least about 15°, at least about 20°, at least about 25°,at least about 30°, at least about 35°, at least about 40°, at leastabout 45°, at least about 50°, at least about 55°, at least about 60°,at least about 70°, at least about 80°, or even at least about 85°.Still, the vertical orientation difference may be not greater than about90°, such as not greater than about 85°, not greater than about 80°, notgreater than about 75°, not greater than about 70°, not greater thanabout 65°, not greater than about 60°, such as not greater than about55°, not greater than about 50°, not greater than about 45°, not greaterthan about 40°, not greater than about 35°, not greater than about 30°,not greater than about 25°, not greater than about 20°, such as notgreater than about 15°, not greater than about 10°, or even not greaterthan about 5°. It will be appreciated that the vertical orientationdifference can be within a range between any of the above minimum andmaximum degrees. Control of the vertical orientation difference betweenshaped abrasive particles of the abrasive article 100 may facilitateimproved grinding performance.

As further illustrated, the shaped abrasive particles can be placed onthe backing to have a predetermined tip height. For example, thepredetermined tip height (h_(T1)) 138 of the shaped abrasive particle102 can be the greatest distance between an upper surface of the backing161 and an uppermost surface 143 of the shaped abrasive particle 102. Inparticular, the predetermined tip height 138 of the shaped abrasiveparticle 102 can define the greatest distance above the upper surface ofthe backing 161 that the shaped abrasive particle 102 extends. Asfurther illustrated, the shaped abrasive particle 104 can have apredetermined tip height (h_(T2)) 139 defined as the distance betweenthe upper surface 161 of the backing 101 and an uppermost surface 144 ofthe shaped abrasive particle 104. Measurements may be evaluated viaX-ray, confocal microscopy CT, micromeasure, white-light interferometry,and a combination thereof.

In accordance with an embodiment, the shaped abrasive particle 102 canbe placed on the backing 101 to have a predetermined tip height 138 thatcan be different that than predetermined tip height 139 of the shapedabrasive particle 104. Notably, the difference in the predetermined tipheight (Δh_(T)) can be defined as the difference between the average tipheight 138 and average tip height 139. In accordance with an embodiment,the difference in the predetermined tip height can be at least about0.01(w), wherein (w) is the width of the shaped abrasive particle asdescribed herein. In other instances, the tip height difference can beat least about 0.05(w), at least about 0.1(w), at least about 0.2(w), atleast about 0.4(w), at least about 0.5(w), at least about 0.6(w), atleast about 0.7(w), or even at least about 0.8(w). Still, in onenon-limiting embodiment, the tip height difference can be not greaterthan about 2(w). It will be appreciated that the difference in tipheight can be in a range between any of the minimum and maximum valuesnoted above. Control of the average tip height and more particularly thedifference in average tip height, between shaped abrasive particles ofthe abrasive article 100 can facilitate improved grinding performance.

While reference herein is made to shaped abrasive particles having adifference in average tip height, it will be appreciated that the shapedabrasive particles of the abrasive articles may have a same average tipheight such that there is essentially no difference between the averagetip height between the shaped abrasive particles. For example, asdescribed herein, shaped abrasive particles of a group may be positionedon the abrasive article such that the vertical tip height of each of theshaped abrasive particles of the group is substantially the same.

FIG. 1C includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment. As illustrated, theshaped abrasive particles 102 and 104 can be oriented in a flatorientation relative to the backing 101, wherein at least a portion of amajor surface 174, and particular the major surface having the largestsurface area (i.e., the bottom surface 174 opposite the upper majorsurface 172), of the shaped abrasive particles 102 and 104 can be indirect contact with the backing 101. Alternatively, in a flatorientation, a portion of the major surface 174 may not be in directcontact with the backing 101, but may be the surface of the shapedabrasive particle closest to the upper surface 161 of the backing 101.

FIG. 1D includes a cross-sectional illustration of a portion of anabrasive article in accordance with an embodiment. As illustrated, theshaped abrasive particles 102 and 104 can be oriented in an invertedorientation relative to the backing 101, wherein at least a portion of amajor surface 172 (i.e., the upper major surface 172) of the shapedabrasive particles 102 and 104 can be in direct contact with the backing101. Alternatively, in an inverted orientation, a portion of the majorsurface 172 may not be in direct contact with the backing 101, but maybe the surface of the shaped abrasive particle closest to the uppersurface 161 of the backing 101.

FIG. 2A includes a top view illustration of a portion of an abrasivearticle including shaped abrasive particles in accordance with anembodiment. As illustrated, the abrasive article can include a shapedabrasive particle 102 overlying the backing 101 in a first positionhaving a first rotational orientation relative to a lateral axis 181defining the width of the backing 101 and perpendicular to alongitudinal axis 181. In particular, the shaped abrasive particle 102can have a predetermined rotational orientation defined by a firstrotational angle between a lateral plane 184 parallel to the lateralaxis 181 and a dimension of the shaped abrasive particle 102. Notably,reference herein to a dimension can be reference to a bisecting axis 231of the shaped abrasive particle extending through a center point 221 ofthe shaped abrasive particle 102 along a surface (e.g., a side or anedge) connected to (directly of indirectly) the backing 101.Accordingly, in the context of a shaped abrasive particle positioned ina side orientation, (see, FIG. 1B), the bisecting axis 231 extendsthrough a center point 221 and in the direction of the width (w) of aside 171 closest to the surface 181 of the backing 101. Moreover, thepredetermined rotational orientation can be defined as the smallestangle 201 with the lateral plane 184 extending through the center point221. As illustrated in FIG. 2A, the shaped abrasive particle 102 canhave a predetermined rotational angle defined as the smallest anglebetween a bisecting axis 231 and the lateral plane 184. In accordancewith an embodiment, the rotational angle 201 can be 0°. In otherembodiments, the rotational angle can be greater, such as at least about2°, at least about 5°, at least about 10°, at least about 15°, at leastabout 20°, at least about 25°, at least about 30°, at least about 35°,at least about 40°, at least about 45°, at least about 50°, at leastabout 55°, at least about 60°, at least about 70°, at least about 80°,or even at least about 85°. Still, the predetermined rotationalorientation as defined by the rotational angle 201 may be not greaterthan about 90°, such as not greater than about 85°, not greater thanabout 80°, not greater than about 75°, not greater than about 70°, notgreater than about 65°, not greater than about 60°, such as not greaterthan about 55°, not greater than about 50°, not greater than about 45°,not greater than about 40°, not greater than about 35°, not greater thanabout 30°, not greater than about 25°, not greater than about 20°, suchas not greater than about 15°, not greater than about 10°, or even notgreater than about 5°. It will be appreciated that the predeterminedrotational orientation can be within a range between any of the aboveminimum and maximum degrees.

As further illustrated in FIG. 2A, the shaped abrasive particle 103 canbe at a position 113 overlying the backing 101 and having apredetermined rotational orientation. Notably, the predeterminedrotational orientation of the shaped abrasive particle 103 cancharacterized as the smallest angle between the lateral plane 184parallel to the lateral axis 181 and a dimension defined by a bisectingaxis 232 of the shaped abrasive particle 103 extending through a centerpoint 222 of the shaped abrasive particle 102 in the direction of thewidth (w) of a side closest to the surface 181 of the backing 101. Inaccordance with an embodiment, the rotational angle 208 can be 0°. Inother embodiments, the rotational angle 208 can be greater, such as atleast about 2°, at least about 5°, at least about 10°, at least about15°, at least about 20°, at least about 25°, at least about 30°, atleast about 35°, at least about 40°, at least about 45°, at least about50°, at least about 55°, at least about 60°, at least about 70°, atleast about 80°, or even at least about 85°. Still, the predeterminedrotational orientation as defined by the rotational angle 208 may be notgreater than about 90°, such as not greater than about 85°, not greaterthan about 80°, not greater than about 75°, not greater than about 70°,not greater than about 65°, not greater than about 60°, such as notgreater than about 55°, not greater than about 50°, not greater thanabout 45°, not greater than about 40°, not greater than about 35°, notgreater than about 30°, not greater than about 25°, not greater thanabout 20°, such as not greater than about 15°, not greater than about10°, or even not greater than about 5°. It will be appreciated that thepredetermined rotational orientation can be within a range between anyof the above minimum and maximum degrees.

In accordance with an embodiment, the shaped abrasive particle 102 canhave a predetermined rotational orientation as defined by the rotationalangle 201 that is different that the predetermined rotationalorientation of the shaped abrasive particle 103 as defined by therotational angle 208. In particular, the difference between therotational angle 201 and rotational angle 208 between the shapedabrasive particles 102 and 103 can define a predetermined rotationalorientation difference. In particular instances, the predeterminedrotational orientation difference can be 0°. In other instances, thepredetermined rotation orientation difference between any two shapedabrasive particles can be greater, such as at least about 1°, at leastabout 3°, at least about 5°, at least about 10°, at least about 15°, atleast about 20°, at least about 25°, at least about 30°, at least about35°, at least about 40°, at least about 45°, at least about 50°, atleast about 55°, at least about 60°, at least about 70°, at least about80°, or even at least about 85°. Still, the predetermined rotationalorientation difference between any two shaped abrasive particles may benot greater than about 90°, such as not greater than about 85°, notgreater than about 80°, not greater than about 75°, not greater thanabout 70°, not greater than about 65°, not greater than about 60°, suchas not greater than about 55°, not greater than about 50°, not greaterthan about 45°, not greater than about 40°, not greater than about 35°,not greater than about 30°, not greater than about 25°, not greater thanabout 20°, such as not greater than about 15°, not greater than about10°, or even not greater than about 5°. It will be appreciated that thepredetermined rotational orientation difference can be within a rangebetween any of the above minimum and maximum values.

FIG. 2B includes a perspective view illustration of a portion of anabrasive article including a shaped abrasive particle in accordance withan embodiment. As illustrated, the abrasive article can include a shapedabrasive particle 102 overlying the backing 101 in a first position 112having a first rotational orientation relative to a lateral axis 181defining the width of the backing 101. Certain aspects of a shapedabrasive particles predetermined orientation characteristics may bedescribed by relation to a x, y, z three-dimensional axis asillustrated. For example, the predetermined longitudinal orientation ofthe shaped abrasive particle 102 may be defined by the position of theshaped abrasive particle on the y-axis, which extends parallel to thelongitudinal axis 180 of the backing 101. Moreover, the predeterminedlateral orientation of the shaped abrasive particle 102 may be definedby the position of the shaped abrasive particle on the x-axis, whichextends parallel to the lateral axis 181 of the backing 101.Furthermore, the predetermined rotational orientation of the shapedabrasive particle 102 may be defined as the rotational angle 102 betweenthe x-axis, which corresponds to an axis or plane parallel to thelateral axis 181 and the bisecting axis 231 of the shaped abrasiveparticle 102 extending through the center point 221 of the side 171shaped abrasive particle 102 connected to (directly of indirectly) thebacking 101. As generally illustrated, the shaped abrasive particle 102can further have a predetermined vertical orientation and predeterminedtip height as described herein. Notably, the controlled placement of aplurality of shaped abrasive particles that facilitates control of thepredetermined orientation characteristics described herein is a highlyinvolved process, which has not previously been contemplated or deployedin the industry.

For simplicity of explanation, the embodiments herein reference certainfeatures relative to a plane defined by X, Y, and Z directions. However,it is appreciated and contemplated that abrasive articles can have othershapes (e.g., coated abrasive belts defining an ellipsoidal or loopedgeometry or even coated abrasive sanding disks having an annular-shapedbacking). The description of the features herein is not limited toplanar configurations of abrasive articles and the features describedherein are applicable to abrasive articles of any geometry. In suchinstances wherein the backing has a circular geometry, the longitudinalaxis and lateral axis can be two diameters extending through the centerpoint of the backing and having an orthogonal relationship relative toeach other.

FIG. 3A includes a top view illustration of a portion of an abrasivearticle 300 in accordance with an embodiment. As illustrated, theabrasive article 300 can include a first group 301 of shaped abrasiveparticles, including shaped abrasive particles 311, 312, 313, and 314(311-314). As used herein, a group can refer to a plurality of shapedabrasive particles have at least one (or a combination of) predeterminedorientation characteristic that is the same for each of the shapedabrasive particles. Exemplary predetermined orientation characteristicscan include a predetermined rotational orientation, a predeterminedlateral orientation, a predetermined longitudinal orientation, apredetermined vertical orientation, and a predetermined tip height. Forexample, the first group 301 of shaped abrasive particles includes aplurality of shaped abrasive particles having substantially the samepredetermined rotational orientation with respect to each other. Asfurther illustrated, the abrasive article 300 can include another group303 including a plurality of shaped abrasive particles, including forexample shaped abrasive particles 321, 322, 323, and 324 (321-324). Asillustrated, the group 303 can include a plurality of shaped abrasiveparticles having a same predetermined rotational orientation.Furthermore, at least a portion of the shaped abrasive particles of thegroup 303 can have a same predetermined lateral orientation with respectto each other (e.g., shaped abrasive particles 321 and 322 and shapedabrasive particles 323 and 324). Moreover, at least a portion of theshaped abrasive particles of the group 303 can have a same predeterminedlongitudinal orientation with respect to each other (e.g., shapedabrasive particles 321 and 324 and shaped abrasive particles 322 and323).

As further illustrated, the abrasive article can include a group 305.The group 305 can include a plurality of shaped abrasive particles,including shaped abrasive particles 331, 332, and 333 (331-333) havingat least one common predetermined orientation characteristic. Asillustrated in the embodiment of FIG. 3A, the plurality of shapedabrasive particles within the group 305 can have a same predeterminedrotational orientation with respect to each other. Furthermore, at leasta portion of the plurality of shaped abrasive particles of the group 305can have a same predetermined lateral orientation with respect to eachother (e.g., shaped abrasive particles 332 and 333). In addition, atleast a portion of the plurality of shaped abrasive particles of thegroup 305 can have a same predetermined longitudinal orientation withrespect to each other. Utilization of groups of shaped abrasiveparticles, and particularly, a combination of groups of shaped abrasiveparticles having the features described herein may facilitate improvedperformance of the abrasive article.

As further illustrated, the abrasive article 300 can include groups 301,303, and 305, which may be separated by channel regions 307 and 308extending between the groups 301, 303, 305. In particular instances, thechannel regions can be regions on the abrasive article that can besubstantially free of shaped abrasive particles. Moreover, the channelregions 307 and 308 may be configured to move liquid between the groups301, 303, and 305, which may improve swarf removal and grindingperformance of the abrasive article. The channel regions 307 and 308 canbe predetermined regions on the surface of the shaped abrasive article.The channel regions 307 and 308 may define dedicated regions betweengroups 301, 303, and 305 that are different, and more particularly,greater in width and/or length, than the longitudinal space or lateralspace between adjacent shaped abrasive particles in the groups 301, 303,and 305.

The channel regions 307 and 308 can extend along a direction that isparallel or perpendicular to the longitudinal axis 180 or parallel orperpendicular to the lateral axis 181 of the backing 101. In particularinstances, the channel regions 307 and 308 can have axes, 351 and 352respectively, extending along a center of the channel regions 307 and308 and along a longitudinal dimension of the channel regions 307 and308 can have a predetermined angle relative to the longitudinal axis 380of the backing 101. Moreover, the axes 351 and 352 of the channelregions 307 and 308 may form a predetermined angle relative to thelateral axis 181 of the backing 101. Controlled orientation of thechannel regions may facilitate improved performance of the abrasivearticle.

Furthermore, the channel regions 307 and 308 may be formed such thatthey have a predetermined orientation relative to the direction ofgrinding 350. For example, the channel regions 307 and 308 can extendalong a direction that is parallel or perpendicular to the direction ofgrinding 350. In particular instances, the channel regions 307 and 308can have axes, 351 and 352 respectively, extending along a center of thechannel regions 307 and 308 and along a longitudinal dimension of thechannel regions 307 and 308 can have a predetermined angle relative tothe direction of grinding 350. Controlled orientation of the channelregions may facilitate improved performance of the abrasive article.

For at least one embodiment, as illustrated the group 301 can include aplurality of shaped abrasive particles, wherein at least a portion ofthe plurality of shaped abrasive particles in the group 301 can define apattern 315. As illustrated, the plurality of shaped abrasive particles311-314 can be arranged with respect to each other in a predetermineddistribution that further defines a two-dimensional array, such as inthe form of a quadrilateral, as viewed top-down. An array is a patternhaving short range order defined by a unit arrangement of shapedabrasive particles and further having long range order including regularand repetitive units linked together. It will be appreciated that othertwo-dimensional arrays can be formed, including other polygonal shapes,ellipsis, ornamental indicia, product indicia, or other designs. Asfurther illustrated, the group 303 can include the plurality of shapedabrasive particles 321-324 that can also be arranged in a pattern 325defining a quadrilateral two-dimensional array. Furthermore, the group305 can include a plurality of shaped abrasive particles 331-334 whichcan be arranged with respect to each other to define a predetermineddistribution in the form of a triangular pattern 335.

In accordance with an embodiment, the plurality of shaped abrasiveparticles of a group 301 may define a pattern that is different than theshaped abrasive particles of another group (e.g., group 303 or 305). Forexample, the shaped abrasive particles of the group 301 may define apattern 315 that is different than the pattern 335 of the group 305 withrespect to the orientation on the backing 101. Moreover, the shapedabrasive particles of the group 301 may define a pattern 315 that has afirst orientation relative to the direction of grinding 350 as comparedto the orientation of the pattern of a second group (e.g., 303 or 305)relative to the direction of grinding 350.

Notably, any one of the groups (301, 303, or 305) of the shaped abrasiveparticles can have a pattern defining one or more vectors (e.g., 361 or362 of group 305) that can have a particular orientation relative to thedirection of grinding. In particular, the shaped abrasive particles of agroup can have a predetermined orientation characteristic that define apattern of the group, which may further define one or more vectors ofthe pattern. In an exemplary embodiment, the vectors 361 and 362 of thepattern 335 can be controlled to form a predetermined angle relative tothe grinding direction 350. The vectors 361 and 362 may have variousorientations including for example, a parallel orientation,perpendicular orientation, or even a non-orthogonal or non-parallelorientation (i.e., angled to define an acute angle or obtuse angle)relative to the grinding direction 350.

In accordance with an embodiment, the plurality of shaped abrasiveparticles of the first group 301 can have at least one predeterminedorientation characteristic that is different than the plurality ofshaped abrasive particles in another group (e.g. 303 or 305). Forexample, at least a portion of the shaped abrasive particles of thegroup 301 can have a predetermined rotational orientation that isdifferent than the predetermined rotational orientation of at least aportion of the shaped abrasive particles of the group 303. Still, in oneparticular aspect, all of the shaped abrasive particles of the group 301can have a predetermined rotational orientation that is different thanthe predetermined rotational orientation of all of the shaped abrasiveparticles of the group 303.

In accordance with another embodiment, at least a portion of the shapedabrasive particles of the group 301 can have a predetermined lateralorientation that is different than the predetermined lateral orientationof at least a portion of the shaped abrasive particles of the group 303.For yet another embodiment, all of the shaped abrasive particles of thegroup 301 can have a predetermined lateral orientation that is differentthan the predetermined lateral orientation of all of the shaped abrasiveparticles of the group 303.

Moreover, in another embodiment, at least a portion of the shapedabrasive particles of the group 301 can have a predeterminedlongitudinal orientation that may be different than the predeterminedlongitudinal orientation of at least a portion of the shaped abrasiveparticles of the group 303. For another embodiment, all of the shapedabrasive particles of the group 301 can have a predeterminedlongitudinal orientation that may be different than the predeterminedlongitudinal orientation of all of the shaped abrasive particles of thegroup 303.

Furthermore, at least a portion of the shaped abrasive particles of thegroup 301 can have a predetermined vertical orientation that isdifferent than the predetermined vertical orientation of at least aportion of the shaped abrasive particles of the group 303. Still, forone aspect, all of the shaped abrasive particles of the group 301 canhave a predetermined vertical orientation that is different than thepredetermined vertical orientation of all of the shaped abrasiveparticles of the group 303

Moreover, in one embodiment, at least a portion of the shaped abrasiveparticles of the group 301 may have a predetermined tip height that isdifferent than the predetermined tip height of at least a portion of theshaped abrasive particles of the group 303. In yet another particularembodiment, all of the shaped abrasive particles of the group 301 mayhave a predetermined tip height that is different than the predeterminedtip height of all of the shaped abrasive particles of the group 303.

It will be appreciated that any number of groups may be included in theabrasive article creating various regions on the abrasive article havingpredetermined orientation characteristics. Moreover, each of the groupscan be different from each other as described in the foregoing for thegroups 301 and 303.

As described in one or more embodiments herein, the shaped abrasiveparticles can be arranged in a predetermined distribution defined bypredetermined positions on the backing. More notably, the predetermineddistribution can define a non-shadowing arrangement between two or moreshaped abrasive particles. For example, in one particular embodiment,the abrasive article can include a first shaped abrasive particle in afirst predetermined position and a second shaped abrasive particle in asecond predetermined position, such that the first and second shapedabrasive particle define a non-shadowing arrangement relative to eachother. A non-shadowing arrangement can be defined by an arrangement ofthe shaped abrasive particles such that they are configured to makeinitial contact with the workpiece at separate locations on theworkpiece and limiting or avoiding an initial overlap in the location ofinitial material removal on the workpiece. A non-shadowing arrangementcan facilitate improved grinding performance. In one particularembodiment, the first shaped abrasive particle can be part of a groupdefined by a plurality of shaped abrasive particles, and the secondshaped abrasive particle can be part of a second group defined by aplurality of shaped abrasive particles. The first group can define afirst row on the backing and the second group can define a second row onthe backing, and each of the shaped abrasive particles of the secondgroup can be staggered relative to each of the shaped abrasive particlesof the first group, thus defining a particular non-shadowingarrangement.

FIG. 3B includes a perspective view illustration of a portion of anabrasive article including shaped abrasive particles havingpredetermined orientation characteristics relative to a grindingdirection in accordance with an embodiment. In one embodiment, theabrasive article can include a shaped abrasive particle 102 having apredetermined orientation relative to another shaped abrasive particle103 and/or relative to a grinding direction 385. Control of one or acombination of predetermined orientation characteristics relative to thegrinding direction 385 may facilitate improved grinding performance ofthe abrasive article. The grinding direction 385 may be an intendeddirection of movement of the abrasive article relative to a workpiece ina material removal operation. In particular instances, the grindingdirection 385 may be related to the dimensions of the backing 101. Forexample, in one embodiment, the grinding direction 385 may besubstantially perpendicular to the lateral axis 181 of the backing andsubstantially parallel to the longitudinal axis 180 of the backing 101.The predetermined orientation characteristics of the shaped abrasiveparticle 102 may define an initial contact surface of the shapedabrasive particle 102 with a workpiece. For example, the shaped abrasiveparticle 102 can have a major surfaces 363 and 364, and side surfaces365 and 366 extending between the major surfaces 363 and 364. Thepredetermined orientation characteristics of the shaped abrasiveparticle 102 can position the particle such that the major surface 363is configured to make initial contact with a workpiece before the othersurfaces of the shaped abrasive particle 102. Such an orientation may beconsidered a frontal orientation relative to the grinding direction 385.More particularly, the shaped abrasive particle 102 can have a bisectingaxis 231 having a particular orientation relative to the grindingdirection. For example, as illustrated, the vector of the grindingdirection 385 and the bisecting axis 231 are substantially perpendicularto each other. It will be appreciated that just as any range ofpredetermined rotational orientations are contemplated for a shapedabrasive particle, any range of orientations of the shaped abrasiveparticles relative to the grinding direction 385 are contemplated andcan be utilized.

The shaped abrasive particle 103 can have different predeterminedorientation characteristics relative to the shaped abrasive particle 102and the grinding direction 385. As illustrated, the shaped abrasiveparticle 103 can include major surfaces 391 and 392, which can be joinedby side surfaces 371 and 372. Moreover, as illustrated, the shapedabrasive particle 103 can have a bisecting axis 373 forming a particularangle relative to the vector of the grinding direction 385. Asillustrated, the bisecting axis 373 of the shaped abrasive particle 103can have a substantially parallel orientation with the grindingdirection 385 such that the angle between the bisecting axis 373 and thegrinding direction 385 is essentially 0 degrees. Accordingly, thepredetermined orientation characteristics of the shaped abrasiveparticle facilitate initial contact of the side surface 372 with aworkpiece before any of the other surfaces of the shaped abrasiveparticle. Such an orientation of the shaped abrasive particle 103 may beconsidered a sideways orientation relative to the grinding direction385.

It will be appreciated that the abrasive article can include one or moregroups of shaped abrasive particles that can be arranged in apredetermined distribution relative to each other, and more particularlycan have distinct predetermined orientation characteristics that definegroups of shaped abrasive particles. The groups of shaped abrasiveparticles, as described herein, can have a predetermined orientationrelative to a grinding direction. Moreover, the abrasive articles hereincan have one or more groups of shaped abrasive particles, each of thegroups having a different predetermined orientation relative to agrinding direction. Utilization of groups of shaped abrasive particleshaving different predetermined orientations relative to a grindingdirection can facilitate improved performance of the abrasive article.

FIG. 4 includes a top view illustration of a portion of an abrasivearticle in accordance with an embodiment. In particular, the abrasivearticle 400 can include a first group 401 including a plurality ofshaped abrasive particles. As illustrated, the shaped abrasive particlescan be arranged relative to each other to define a predetermineddistribution. More particularly, the predetermined distribution can bein the form of a pattern 423 as viewed top-down, and more particularlydefining a triangular shaped two-dimensional array. As furtherillustrated, the group 401 can be arranged on the abrasive article 400defining a predetermined microunit 431 overlying the backing 101. Inaccordance with an embodiment, the microunit 431 can have a particulartwo-dimensional shape as viewed top-down. Some exemplary two-dimensionalshapes can include polygons, ellipsoids, numerals, Greek alphabetcharacters, Latin alphabet characters, Russian alphabet characters,Arabic alphabet characters, Kanji characters, complex shapes, designs,any a combination thereof. In particular instances, the formation of agroup having a particular microunit may facilitate improved performanceof the abrasive article.

As further illustrated, the abrasive article 400 can include a group 404including a plurality of shaped abrasive particles which can be arrangedon the surface of the backing 101 to define a predetermineddistribution. Notably, the predetermined distribution can include anarrangement of the plurality of the shaped abrasive particles thatdefine a pattern, and more particularly, a generally quadrilateralpattern 424. As illustrated, the group 404 can define a microunit 434 onthe surface of the abrasive article 400. In one embodiment, themicrounit 434 of the group 404 can have a two-dimensional shape asviewed top down, including for example a polygonal shape, and moreparticularly, a generally quadrilateral (diamond) shape as viewed topdown on the surface of the abrasive article 400. In the illustratedembodiment of FIG. 4, the group 401 can have a microunit 431 that issubstantially the same as the microunit 434 of the group 404. However,it will be appreciated that in other embodiments, various differentgroups can be used on the surface of the abrasive article, and moreparticularly wherein each of the different groups has a differentmicrounit.

As further illustrated, the abrasive article can include groups 401,402, 403, and 404 which can be separated by channel regions 422 and 421extending between the groups 401-404. In particular instances, thechannel region can be substantially free of shaped abrasive particles.Moreover, the channel regions 421 and 422 may be configured to moveliquid between the groups 401-404 and further improve swarf removal andgrinding performance of the abrasive article. Furthermore, in a certainembodiment, the abrasive article 400 can include channel regions 421 and422 extending between groups 401-404, wherein the channel regions 421and 422 can be patterned on the surface of the abrasive article 400. Inparticular instances, the channel regions 421 and 422 can represent aregular and repeating array of features extending along a surface of theabrasive article.

FIG. 5 includes a top view of a portion of an abrasive article inaccordance with an embodiment. Notably, the abrasive article 500 caninclude shaped abrasive particles 501 overlying, and more particularly,coupled to the backing 101. In at least one embodiment, the abrasivearticles of the embodiments herein, can include a row 511 of shapedabrasive particles. The row 511 can include a group of shaped abrasiveparticles 501, wherein each of the shaped abrasive particles 501 withinthe row 511 can have a same predetermined lateral orientation withrespect to each other. In particular, as illustrated, each of the shapedabrasive particles 501 of the row 511 can have a same predeterminedlateral orientation with respect to the lateral axis 551. Moreover, eachof the shaped abrasive particles 501 of the first row 511 may be part ofa group and thus having at least one other predetermined orientationcharacteristic that is the same relative to each other. For example,each of the shaped abrasive particles 501 of the row 511 can be part ofa group having a same predetermined vertical orientation, and may definea vertical company. In at least another embodiment, each of the shapedabrasive particles 501 of the row 511 can be part of a group having asame predetermined rotational orientation, and may define a rotationalcompany. Moreover, each of the shaped abrasive particles 501 of the row511 can be part of a group having a same predetermined tip height withrespect to each other, and may define a tip height company. Moreover, asillustrated, the abrasive article 500 can include a plurality of groupsin the orientation of the row 511, which may be spaced apart from eachother along the longitudinal axis 180, and more particularly, separatedfrom each other by other intervening rows, including for example, rows521, 531, and 541.

As further illustrated in FIG. 5, the abrasive article 500 can includeshaped abrasive particles 502 which may be arranged relative to eachother to define a row 521. The row 521 of shaped abrasive particles 502can include any of the features described in accordance with the row511. Notably, the shaped abrasive particles 502 of the row 521 may havea same predetermined lateral orientation with respect to each other.Furthermore, the shaped abrasive particles 502 of the row 521 may haveat least one predetermined orientation characteristic that is differentthan a predetermined orientation characteristic of any one the shapedabrasive particles 501 of the row 511. For example, as illustrated, eachof the shaped abrasive particles 502 of the row 521 can have a samepredetermined rotational orientation that is different than thepredetermined rotational orientation of each of the shaped abrasiveparticles 501 of the row 511.

In accordance with another embodiment, the abrasive article 500 caninclude shaped abrasive particles 503 arranged relative to each otherand defining a row 531. The row 531 can have any of the characteristicsas described in accordance with other embodiments, particularly withrespect to row 511 or row 521. Furthermore, as illustrated, each of theshaped abrasive particles 503 within the row 531 can have at least onepredetermined orientation characteristic that is the same with respectto each other. Moreover, each of the shaped abrasive particles 503within the row 531 can have at least one predetermined orientationcharacteristic that is different than a predetermined orientationcharacteristic relative to any one of the shaped abrasive particles 501of row 511 or the shaped abrasive particles 502 of row 521. Notably, asillustrated, each of the shaped abrasive particles 503 of row 531 canhave a same predetermined rotational orientation that is different withrespect to the predetermined rotational orientation of the shapedabrasive particles 501 and row 511 and the predetermined rotationalorientation of the shaped abrasive particles 502 and row 521.

As further illustrated, the abrasive article 500 can include shapedabrasive particles 504 arranged relative to each other and defining arow 541 on the surface of the abrasive article 500. As illustrated, eachof the shaped abrasive particles 504 and the row 541 can have at leastone of the same predetermined orientation characteristic. Furthermore,in accordance with an embodiment, each of the shaped abrasive particles504 can have at least one of the same predetermined orientationcharacteristic, such as a predetermined rotational orientation that isdifferent than the predetermined rotational orientation of any of theshaped abrasive particles 501 of row 511, the shaped abrasive particles502 of the row 521, and the shaped abrasive particles 503 of the row531.

As further illustrated, the abrasive article 500 can include a column561 of shaped abrasive particles including at least one shaped abrasiveparticle from each of the rows 511, 521, 531, and 541. Notably, each ofthe shaped abrasive particles within the column 561 can share at leastone predetermined orientation characteristic, and more particularly atleast a predetermined longitudinal orientation with respect to eachother. As such, each of the shaped abrasive particles within the column561 can have a predetermined longitudinal orientation with respect toeach other and a longitudinal plane 562. In certain instances, thearrangement of shaped abrasive particles in groups, which can includethe arrangement of shaped abrasive particles in rows, columns, verticalcompanies, rotational companies, and tip height companies can facilitateimproved performance of the abrasive article.

FIG. 6 includes a top view illustration of a portion of an abrasivearticle in accordance with an embodiment. Notably, the abrasive article600 can include shaped abrasive particles 601 that can be arrangedrelative to each other to define a column 621 extending along alongitudinal plane 651 and having at least one of the same predeterminedorientation characteristics relative to each other. For example, each ofthe shaped abrasive particles 601 of the company 621 can have a samepredetermined longitudinal orientation with respect to each other andthe longitudinal axis 651. It will be appreciated that the shapedabrasive particles 601 of the column 621 can share at least one otherpredetermined orientation characteristic, including for example a samepredetermined rotational orientation with respect to each other.

As further illustrated, the abrasive article 600 can include shapedabrasive particles 602 arranged relative to each other on the backing101 and defining a column 622 with respect to each other along alongitudinal plane 652. It will be appreciated that the shaped abrasiveparticles 602 of the column 622 can share at least one otherpredetermined orientation characteristic, including for example a samepredetermined rotational orientation with respect to each other. Still,each of the shaped abrasive particles 602 of the column 622 can define agroup having at least one predetermined orientation characteristicdifferent than at least one predetermined orientation characteristic ofat least one of the shaped abrasive particles 621 of the column 621.More particularly, each of the shaped abrasive particles 602 of thecolumn 622 can define a group having a combination of predeterminedorientation characteristics different than a combination ofpredetermined orientation characteristics of the shaped abrasiveparticles 601 of the column 621.

Furthermore, as illustrated, the abrasive article 600 can include shapedabrasive particles 603 having a same predetermined longitudinalorientation with respect to each other along the a longitudinal plane653 on the backing 101 and defining a column 623. Still, each of theshaped abrasive particles 603 of the column 623 can define a grouphaving at least one predetermined orientation characteristic differentthan at least one predetermined orientation characteristic of at leastone of the shaped abrasive particles 621 of the column 621 and theshaped abrasive particles 602 of the column 622. More particularly, eachof the shaped abrasive particles 603 of the column 623 can define agroup having a combination of predetermined orientation characteristicsdifferent than a combination of predetermined orientationcharacteristics of the shaped abrasive particles 601 of the column 621and the shaped abrasive particles 602 of the column 622.

FIG. 7A includes a top down view of a portion of an abrasive article inaccordance with an embodiment. In particular instances, the abrasivearticles herein may further include orientation regions that facilitateplacement of shaped abrasive particles in the predeterminedorientations. The orientation regions can be coupled to the backing 101of the abrasive article. Alternatively, the orientation regions can bepart of an adhesive layer, including for example a make coat or a sizecoat. In still another embodiment, the orientation regions can beoverlying the backing 101 or even more particularly integrated with thebacking 101.

As illustrated in FIG. 7A, the abrasive article 700 can include shapedabrasive particles 701, 702, 703, (701-703) and each of the shapedabrasive particles 701-703 can be coupled with a respective orientationregion 721, 722, and 723 (721-723). In accordance with an embodiment,the orientation region 721 can be configured to define at least one (ora combination of) predetermined orientation characteristic of the shapedabrasive particle 701. For example, the orientation region 721 can beconfigured to define a predetermined rotational orientation, apredetermined lateral orientation, a predetermined longitudinalorientation, a predetermined vertical orientation, a predetermined tipheight, and a combination thereof with respect to the shaped abrasiveparticle 701. Furthermore, in a particular embodiment, the orientationregions 721, 722 and 723 can be associated with a plurality of shapedabrasive particles 701-703 and can define a group 791.

According to one embodiment, the orientation regions 721-723 can beassociated with an alignment structure, and more particularly, part ofan alignment structure (e.g., discrete contact regions) as described inmore detail herein. The orientation regions 721-723 can be integratedwithin any of the components of the abrasive article, including forexample, the backing 101 or adhesive layers, and thus may be consideredcontact regions as described in more detail herein. Alternatively, theorientation regions 721-723 can be associated with an alignmentstructure use in forming the abrasive article, which may be a separatecomponent from the backing and integrated within the abrasive article,and which may not necessarily form a contact region associated with theabrasive article.

As further illustrated, the abrasive article 700 can further includeshaped abrasive particles 704, 705, 706 (704-706), wherein each of theshaped abrasive particles 704-706 can be associated with an orientationregion 724, 725, 726, respectively. The orientation regions 724-726 canbe configured to control at least one predetermined orientationcharacteristic of the shaped abrasive particles 704-706. Moreover, theorientation regions 724-726 can be configured to define a group 792 ofshaped abrasive particle 704-706. In accordance with an embodiment, theorientation regions 724-726 can be spaced apart from the orientationregions 721-723. More particularly the orientation regions 724-726 canbe configured to define a group 792 having at least one predeterminedorientation characteristic that is different than a predeterminedorientation characteristic of the shaped abrasive particles 701-703 ofthe group 791.

FIG. 7B includes an illustration of a portion of an abrasive articleaccording to an embodiment. In particular, FIG. 7B includes anillustration of particular embodiments of alignment structures andcontact regions that may be utilized and configured to facilitate atleast one predetermined orientation characteristic of one or more shapedabrasive particles associated with the alignment structure and contactregions.

FIG. 7B includes a portion of an abrasive article including a backing101 a first group 791 of shaped abrasive particles 701 and 702 overlyingthe backing 101, a second group 792 of shaped abrasive particles 704 and705 overlying the backing 101, a third group 793 of shaped abrasiveparticles 744 and 745 overlying the backing 101, and a fourth group 794of shaped abrasive particles 746 and 747 overlying the backing 101. Itwill be appreciated that while various and multiple different groups791, 792, 793, and 794 are illustrated, the illustration is in no waylimiting and the abrasive articles of the embodiments herein can includeany number and arrangement of groups.

The abrasive article of FIG. 7B further includes an alignment structure761 having a first contact region 721 and a second contact region 722.The alignment structure 761 can be used to facilitate placement of theshaped abrasive particles 701 and 702 in desired orientations on thebacking and relative to each other. The alignment structure 761 of theembodiments herein can be a permanent part of the abrasive article. Forexample, the alignment structure 761 can include contact regions 721 and722, which can overlie the backing 101, and in some instances, directlycontact the backing 101. In particular instances, the alignmentstructure 761 may be integral with the abrasive article, and may overliethe backing, underlie an adhesive layer overlying the backing, or evenbe integral part of one or more adhesive layers overlying the backing.

According to one embodiment, the alignment structure 761 can beconfigured to deliver and in particular instances, temporarily orpermanently hold the shaped abrasive particle 701 at a first position771. In particular instances, such as illustrated in FIG. 7B, thealignment structure 761 can include a contact region 721, which can havea particular two-dimensional shape as viewed top down and defined by thewidth of the contact region (w_(cr)) and the length of the contactregion (l_(cr)), wherein the length is the longest dimension of thecontact region 721. According to at least one embodiment, the contactregion can be formed to have a shape (e.g., a two-dimensional shape),which may facilitate controlled orientation of the shaped abrasiveparticle 701. More particularly, the contact region 721 can have atwo-dimensional shape configured to control one or more (e.g., at leasttwo of) a particular predetermined orientation characteristic, includingfor example, a predetermined rotational orientation, a predeterminedlateral orientation, and a predetermined longitudinal orientation.

In particular instances, the contact regions 721 and 722 can be formedto have controlled two-dimensional shapes that may facilitate apredetermined rotational orientation of the corresponding shapedabrasive particles 701 and 702. For example, the contact region 721 canhave a controlled and predetermined two-dimensional shape configured todetermine a predetermined rotational orientation of the shaped abrasiveparticle 701. Moreover, the contact region 722 can have a controlled andpredetermined two-dimensional shape configured to determine apredetermined rotational orientation of the shaped abrasive particle702.

As illustrated, the alignment structure can include a plurality ofdiscrete contact regions 721 and 722, wherein each of the contactregions 721 and 722 can be configured to deliver, and temporarily orpermanently hold, one or more shaped abrasive particles. In someinstances, the alignment structure can include a web, a fibrousmaterial, a mesh, a solid structure having openings, a belt, a roller, apatterned material, a discontinuous layer of material, a patternedadhesive material, and a combination thereof.

The plurality of contact regions 721 and 722 can define at least one ofthe predetermined rotational orientation of a shaped abrasive particle,a predetermined rotational orientation difference between at least twoshaped abrasive particles, the predetermined longitudinal orientation ofa shaped abrasive particle, a longitudinal space between two shapedabrasive particles, the predetermined lateral orientation, a lateralspace between two shaped abrasive particles, a predetermined verticalorientation, a predetermined vertical orientation difference between twoshaped abrasive particles, a predetermined tip height, a predeterminedtip height difference between two shaped abrasive particles. Inparticular instances, as illustrated in FIG. 7B, the plurality ofdiscrete contact regions can include a first contact region 721 and asecond contact region 722 distinct from the first contact region 721.While the contact regions 721 and 722 are illustrated as having the samegeneral shape relative to each other, as will become evident in based onfurther embodiments described herein, the first contact region 721 andsecond contact region 722 can be formed to have differenttwo-dimensional shapes. Furthermore, while not illustrated, it will beappreciated that alignment structures of the embodiments herein caninclude first and second contact regions configured to deliver andcontain shaped abrasive particles in different predetermined rotationalorientations with respect to each other.

In one particular embodiment, the contact regions 721 and 722 can have atwo-dimensional shape selected from the group consisting of polygons,ellipsoids, numerals, crosses, multi-armed polygons, Greek alphabetcharacters, Latin alphabet characters, Russian alphabet characters,Arabic alphabet characters, rectangle, quadrilateral, pentagon, hexagon,heptagon, octagon, nonagon, decagon, and a combination thereof.Moreover, while the contact regions 721 and 722 are illustrated ashaving substantially the same two-dimensional shape, it will beappreciated, that in alternative embodiments, the contact regions 721and 722 can have different two-dimensional shapes. Two-dimensionalshapes are the shapes of the contact regions 721 and 722 as viewed inthe plane of the length and width of the contact regions, which may bethe same plane defined by the upper surface of the backing.

Moreover, it will be appreciated that the alignment structure 761 may bea temporary part of the abrasive article. For example, the alignmentstructure 761 can represent a template or other object that temporarilyfixes the shaped abrasive particles at the contact regions, facilitatingplacement of the shaped abrasive particles in a desired position havingone or more predetermined orientation characteristics. After placementof the shaped abrasive particles, the alignment structure may be removedleaving the shaped abrasive particle on the backing in the predeterminedpositions.

According to one particular embodiment, the alignment structure 761 canbe a discontinuous layer of material including the plurality of contactregions 721 and 722 that may be made of an adhesive material. In moreparticular instances, the contact region 721 can be configured to adhereat least one shaped abrasive particle. In other embodiments, the contactregion 721 can be formed to adhere more than one shaped abrasiveparticle. It will be appreciated that according to at least oneembodiment, the adhesive material can include an organic material, andmore particularly, at least one resin material.

Furthermore, the plurality of contact regions 721 and 722 can bearranged on the surface of the backing 101 to define a predetermineddistribution of contact regions. The predetermined distribution ofcontact regions can have any characteristic of predetermineddistributions described herein. In particular, the predetermineddistribution of contact regions can define a controlled, non-shadowarrangement. The predetermined distribution of contact regions candefine and substantially correspond to a same predetermined distributionof shaped abrasive particles on the backing, wherein each contact regioncan define a position of a shaped abrasive particle.

As illustrated, in certain instances, the contact regions 721 and 722can be spaced apart from each other. In at least one embodiment, thecontact regions 721 and 722 can be spaced apart from each other by adistance 731. The distance 731 between contact regions 721 and 722 isgenerally the smallest distance between adjacent contact regions 721 and722 in a direction parallel to the lateral axis 181 or longitudinal axis180.

In accordance with one embodiment, the discrete contact regions of theplurality of discrete contact regions can be spaced apart from eachother by a gap distance extending in any direction between adjacentdiscrete contact regions and over a non-contact region, whereinessentially no adhesive material is provided on the backing 101. Forexample, the gap distance may be the distance 731 between the discretecontact regions 721 and 722 a direction parallel to the lateral axis181. Alternatively, in another embodiment, the gap distance can be adistance 732 extending in a direction parallel to the longitudinal axis180. The foregoing examples are non-limiting and the gap distance mayextend in any variety of directions depending on the shortest distancebetween a first discrete contact region and a second contact region,while extending over a non-contact region. In one embodiment, the gapdistance can be at least about 0.5(w), wherein (w) corresponds to awidth of a body of a shaped abrasive particle. In other instances, thegap distance can be at least about 0.7(w), at least about 0.9(w), atleast about 1(w), at least about 1.1(w), at least about 1.3(w). Still,in a non-limiting embodiment, the gap distance can be not greater thanabout 100(w), not greater than about 50(w). The formation of discretecontact regions of certain dimensions may improve processing over othermethods using a continuous coating of material. For example, in certaininstances, use of a discontinuous coating comprising discrete contactregions can reduce processing time and reduce blistering associated withabrasive articles using a continuous coating of material. Moreover, andunexpectedly, the shaped abrasive may experience improved anchoringusing a discontinuous coating as opposed to a continuous coating.

For another embodiment, the gap distance can be at least about 0.1 mm,such as at least about 0.5 mm, at least about 1 mm, at least about 2 mm,or even at least about 2.5 mm. Yet, in another non-limiting embodiment,the gap distance can be not greater than about 50 mm, such as notgreater than about 40 mm, or not greater than about 20 mm.

In certain instances, the discrete contact regions 721 and 722 can havea particular width (w_(cr)) relative to a dimension of a body of ashaped abrasive particle, which can facilitate the features of theembodiments herein. For example, the discrete containment region 721 canhave a width (w_(cr)) defining a minimum dimension of the discretecontainment region that can be at least about 0.5(h), wherein (h) is aheight of a body of a shaped abrasive particle as described inembodiments herein. In other instance, the width of the discrete contactregion 721 can be at least about 0.7(h), such as at least about 0.9(h),at least about 1(h), at least about 1.1(h), at least about 1.3(h).Still, in a non-limiting embodiment, the width of the discrete contactregion 721 can be not greater than about 100(h), such as not greaterthan about 50(h). It will be appreciated that the width of the discretecontact region 721 can be within a range between any of the minimum andmaximum values noted above. Furthermore, it will be appreciated that thewidth of the discrete contact region 721 can be attributed to any otherdiscrete contact regions of the embodiments herein, and furtherunderstood that a width can correlate to a diameter in the context of adiscrete contact region having a circular shape (e.g., discrete contactregion 763).

For another embodiment, the width of the discrete contact region 721 canbe not greater than about 5 mm, such as not greater than about 4 mm, notgreater than about 3 mm, not greater than about 2 mm, not greater thanabout 1 mm, or even not greater than about 0.8 mm. Still, in anothernon-limiting embodiment, the width of the discrete contact region 721can be at least about 0.01 mm, such as at least about 0.05 mm, or evenat least about 0.1 mm. It will be appreciated that the width of thediscrete contact region 721 can be within a range between any of theminimum and maximum values noted above. Furthermore, it will beappreciated that the width of the discrete contact region 721 can beattributed to any other discrete contact regions of the embodimentsherein, and further understood that a width can correlate to a diameterin the context of a discrete contact region having a circular shape(e.g., discrete contact region 763).

Control of the size and shape of the discrete contact regions may beachieved by controlling a rheology of an adhesive material used to formeach of the discrete contact regions of the plurality of discretecontact regions. However, it will be appreciated that other such processcontrols may be utilized.

In an alternative embodiment, the plurality of discrete contact regions721 and 722 can be openings in a structure, such as a substrate. Forexample, each of the contact regions 721 and 722 can be openings in atemplate that is used to temporarily place the shaped abrasive particlesin particular positions on the backing 101. The plurality of openingscan extend partially or entirely through the thickness of the alignmentstructure. Alternatively, the contact regions 7821 and 722 can beopenings in a structure, such as a substrate or layer that ispermanently part of the backing and final abrasive article. The openingscan have particular cross-sectional shapes that may be complementary toa cross-sectional shape of the shaped abrasive particles to facilitateplacement of the shaped abrasive particles in predetermined positionsand with one or more predetermined orientation characteristics.

Moreover, according to an embodiment, the alignment structure caninclude a plurality of discrete contact regions separated by non-contactregions, wherein the non-contact regions are regions distinct from thediscrete contact regions and may be substantially free of the shapedabrasive particles. In one embodiment, the non-contact regions candefine regions configured to be essentially free of adhesive materialand separating contract regions 721 and 722. In one particularembodiment, the non-contact region can define regions configured to beessentially free of shaped abrasive particles.

Various methods may be utilized for form an alignment structure and thediscrete contact regions, including but not limited to process such ascoating, spraying, depositing, printing, etching, masking, removing,molding, casting, stamping, heating, curing, tacking, pinning, fixing,pressing, rolling, stitching, adhering, irradiating, and a combinationthereof. In particular instances, wherein the alignment structure is inthe form of a discontinuous layer of adhesive material, which caninclude a plurality of discrete contact regions including an adhesivematerial spaced apart from each other by non-contact regions, theforming process can include a selective deposition of the adhesivematerial.

As illustrated and noted above, FIG. 7B further includes a second group792 of shaped abrasive particles 704 and 705 overlying the backing 101.The second group 792 can be associated with an alignment structure 762,which can include a first contact region 724 and a second contact region725. The alignment structure 762 can be used to facilitate placement ofthe shaped abrasive particles 704 and 705 in desired orientations on thebacking 101 and relative to each other. As noted herein, the alignmentstructure 762 can have any of the characteristics of alignmentstructures described herein. It will be appreciated that the alignmentstructure 762 can be a permanent or temporary part of the final abrasivearticle. The alignment structure 762 may be integral with the abrasivearticle, and may overlie the backing 101, underlie an adhesive layeroverlying the backing 101, or even be integral part of one or moreadhesive layers overlying the backing 101.

According to one embodiment, the alignment structure 762 can beconfigured to deliver and in particular instances, temporarily orpermanently hold the shaped abrasive particle 704 at a first position773. In particular instances, such as illustrated in FIG. 7B, thealignment structure 762 can include a contact region 724, which can havea particular two-dimensional shape as viewed top down and defined by thewidth of the contact region (w_(cr)) and the length of the contactregion (l_(cr)), wherein the length is the longest dimension of thecontact region 724.

According to at least one embodiment, the contact region 724 can beformed to have a shape (e.g., a two-dimensional shape), which mayfacilitate controlled orientation of the shaped abrasive particle 704.More particularly, the contact region 724 can have a two-dimensionalshape configured to control one or more (e.g., at least two of) aparticular predetermined orientation characteristic, including forexample, a predetermined rotational orientation, a predetermined lateralorientation, and a predetermined longitudinal orientation. In at leastone embodiment, the contact region 724 can be formed to have atwo-dimensional shape, wherein the dimensions of the contact region 724(e.g., length and/or width) substantially correspond to and aresubstantially the same as dimensions of the shaped abrasive particle704, thereby facilitating positioning of the shaped abrasive particle atthe position 772 and facilitating one or a combination of predeterminedorientation characteristics of the shaped abrasive particle 704.Furthermore, according to an embodiment, the alignment structure 762 caninclude a plurality of contact regions having controlled two-dimensionalshapes configured to facilitate and control one or more predeterminedorientation characteristics of associated shaped abrasive particles.

As further illustrated, and according to an embodiment, the alignmentstructure 762 can be configured to deliver and in particular instances,temporarily or permanently hold the shaped abrasive particle 705 at asecond position 774. In particular instances, such as illustrated inFIG. 7B, the alignment structure 762 can include a contact region 725,which can have a particular two-dimensional shape as viewed top down anddefined by the width of the contact region (w_(cr)) and the length ofthe contact region (l_(cr)), wherein the length is the longest dimensionof the contact region 725. Notably, the contact regions 724 and 725 ofthe alignment structure can have a different orientation relative to thecontact regions 721 and 722 of the alignment structure 761 to facilitatedifferent predetermine orientation characteristics between the shapedabrasive particles 701 and 702 of the group 791 and the shaped abrasiveparticles 704 and 705 of the group 792.

As illustrated and noted above, FIG. 7B further includes a third group793 of shaped abrasive particles 744 and 745 overlying the backing 101.The third group 793 can be associated with an alignment structure 763,which can include a first contact region 754 and a second contact region755. The alignment structure 763 can be used to facilitate placement ofthe shaped abrasive particles 744 and 745 in desired orientations on thebacking 101 and relative to each other. As noted herein, the alignmentstructure 763 can have any of the characteristics of alignmentstructures described herein. It will be appreciated that the alignmentstructure 763 can be a permanent or temporary part of the final abrasivearticle. The alignment structure 763 may be integral with the abrasivearticle, and may overlie the backing 101, underlie an adhesive layeroverlying the backing 101, or even be integral part of one or moreadhesive layers overlying the backing 101.

According to one embodiment, the alignment structure 763 can beconfigured to deliver and in particular instances, temporarily orpermanently hold the shaped abrasive particle 744 at a first position775. Likewise, as illustrated, the alignment structure 763 can beconfigured to deliver and in particular instances, temporarily orpermanently hold the shaped abrasive particle 745 at a second position776.

In particular instances, such as illustrated in FIG. 7B, the alignmentstructure 763 can include a contact region 754, which can have aparticular two-dimensional shape as viewed top down. As illustrated, thecontact region 754 can have a circular two-dimensional shape, which canbe defined in part by a diameter (d_(cr)).

According to at least one embodiment, the contact region 754 can beformed to have a shape (e.g., a two-dimensional shape), which mayfacilitate controlled orientation of the shaped abrasive particle 744.More particularly, the contact region 754 can have a two-dimensionalshape configured to control one or more (e.g., at least two of) aparticular predetermined orientation characteristic, including forexample, a predetermined rotational orientation, a predetermined lateralorientation, and a predetermined longitudinal orientation. In at leastone alternative embodiment as illustrated, the contact region 754 canhave a circular shape, which may facilitate some freedom of apredetermined rotational orientation. For example, in comparison of theshaped abrasive particles 744 and 745, each of which are associated withthe contact regions 754 and 755, respectively, and further wherein eachof the contact regions 754 and 755 have circular two-dimensional shapes,the shaped abrasive particles 744 and 745 have different predeterminedrotational orientations with respect to each other. The circulartwo-dimensional shape of the contact regions 754 and 755 may facilitatea preferential side orientation of the shaped abrasive particles 744 and745, while also allowing for a degree of freedom in at least onepredetermined orientation characteristic (i.e., a predeterminedrotational orientation) with respect to each other.

It will be appreciated, that in at least one embodiment, a dimensions ofthe contact region 754 (e.g., diameter) may substantially correspond toand may be substantially the same as a dimension of the shaped abrasiveparticle 744 (e.g., a width of a side surface), which may facilitatepositioning of the shaped abrasive particle 744 at the position 775 andfacilitating one or a combination of predetermined orientationcharacteristics of the shaped abrasive particle 744. Furthermore,according to an embodiment, the alignment structure 763 can include aplurality of contact regions having controlled two-dimensional shapesconfigured to facilitate and control one or more predeterminedorientation characteristics of associated shaped abrasive particles. Itwill be appreciated, that while the foregoing alignment structure 763includes contact regions 754 and 755 having substantially similarshapes, the alignment structure 763 can include a plurality of contactregions having a plurality of different two-dimensional shapes.

As illustrated and noted above, FIG. 7B further includes a fourth group794 of shaped abrasive particles 746 and 747 overlying the backing 101.The fourth group 794 can be associated with an alignment structure 764,which can include a first contact region 756 and a second contact region757. The alignment structure 764 can be used to facilitate placement ofthe shaped abrasive particles 746 and 747 in desired orientations on thebacking 101 and relative to each other. As noted herein, the alignmentstructure 764 can have any of the characteristics of alignmentstructures described herein. It will be appreciated that the alignmentstructure 764 can be a permanent or temporary part of the final abrasivearticle. The alignment structure 764 may be integral with the abrasivearticle, and may overlie the backing 101, underlie an adhesive layeroverlying the backing 101, or even be integral part of one or moreadhesive layers overlying the backing 101.

According to one embodiment, the alignment structure 764 can beconfigured to deliver and in particular instances, temporarily orpermanently hold the shaped abrasive particle 746 at a first position777. Likewise, as illustrated, the alignment structure 764 can beconfigured to deliver and in particular instances, temporarily orpermanently hold the shaped abrasive particle 747 at a second position778.

In particular instances, such as illustrated in FIG. 7B, the alignmentstructure 763 can include a contact region 756, which can have aparticular two-dimensional shape as viewed top down. As illustrated, thecontact region 756 can have a cross-like two-dimensional shape, whichcan be defined in part by a length (l_(cr)).

According to at least one embodiment, the contact region 756 can beformed to have a shape (e.g., a two-dimensional shape), which mayfacilitate controlled orientation of the shaped abrasive particle 746.More particularly, the contact region 756 can have a two-dimensionalshape configured to control one or more (e.g., at least two of) aparticular predetermined orientation characteristic, including forexample, a predetermined rotational orientation, a predetermined lateralorientation, and a predetermined longitudinal orientation. In at leastone alternative embodiment as illustrated, the contact region 756 canhave a cross-shaped two-dimensional shape, which may facilitate somefreedom of a predetermined rotational orientation of the shaped abrasiveparticle 746.

For example, in comparison of the shaped abrasive particles 746 and 747,each of which are associated with the contact regions 756 and 757,respectively, and further wherein each of the contact regions 756 and757 have cross-shaped two-dimensional shapes, the shaped abrasiveparticles 746 and 747 can have different predetermined rotationalorientations with respect to each other. The cross-shapedtwo-dimensional shapes of the contact regions 756 and 757 may facilitatea preferential side orientation of the shaped abrasive particles 746 and747, while also allowing for a degree of freedom in at least onepredetermined orientation characteristic (i.e., a predeterminedrotational orientation) with respect to each other. As illustrated, theshaped abrasive particles 746 and 747 are oriented substantiallyperpendicular to each other. The cross-shaped two-dimensional shape ofthe contact regions 756 and 757 facilitates generally two preferredpredetermined rotational orientations of shaped abrasive particles, eachof which are associated with the direction of the arms of thecross-shaped contact regions 756 and 757, and each of the twoorientations are illustrated by the shaped abrasive particles 746 and747.

It will be appreciated, that in at least one embodiment, a dimensions ofthe contact region 756 (e.g., length) may substantially correspond toand may be substantially the same as a dimension of the shaped abrasiveparticle 746 (e.g., a length of a side surface), which may facilitatepositioning of the shaped abrasive particle 746 at the position 777 andfacilitating one or a combination of predetermined orientationcharacteristics of the shaped abrasive particle 746. Furthermore,according to an embodiment, the alignment structure 764 can include aplurality of contact regions having controlled two-dimensional shapesconfigured to facilitate and control one or more predeterminedorientation characteristics of associated shaped abrasive particles. Itwill be appreciated, that while the foregoing alignment structure 764includes contact regions 756 and 757 having substantially similarshapes, the alignment structure 764 can include a plurality of contactregions having a plurality of different two-dimensional shapes.

Turning briefly to FIG. 7C a top view illustration of a non-shadowingarrangement to be formed on a portion of an abrasive article is providedin accordance with an embodiment. As illustrated, the portion of theabrasive article can include a backing 101, a first group of discretecontact regions 781 extending over the backing 101, a second group ofdiscrete contact regions 782 extending over the backing 101, and a thirdgroup of discrete contact regions 783 extending over the backing 101.Each of the group of discrete contact regions 781, 782, and 783 can havea plurality of discrete contact regions extending linearly over asurface of the backing. Moreover, each of the discrete contact regionswithin a group can extend in substantially the same direction, such thateach of the discrete contact regions within a group can be substantiallyparallel to each other. Yet, the discrete contact regions from differentgroups may intersect each other. For example, each of the discretecontact regions of the first group of discrete contact regions 781 canintersect at least one other discrete contact region from at least oneof the second group of discrete contact regions 782 and the third groupof discrete contact regions 783.

According to an embodiment, each of the discrete contact regions, and inparticular, each of the discrete contact regions within the groups ofdiscrete contact regions 781, 782, and 783 can extend for at least aportion of the width of the backing 101. In certain instances, each ofthe groups of discrete contact regions 781, 782, and 783 can extend forat least a majority of the width of the backing 101, which can bedefined as the distance along the backing 101 in the direction of thelateral axis 181.

In another embodiment, each of the discrete contact regions, and inparticular, each of the groups of discrete contact regions 781, 782, and783 can extend for at least a portion of the length of the backing 101.In certain instances, each of the groups of discrete contact regions781, 782, and 783 can extend for at least a majority of the length ofthe backing 101, which can be defined as the distance along the backing101 in the direction of the longitudinal axis 180. Still, in anothernon-limiting embodiment, only one of the group of discrete contactregions, such as the group of discrete contact regions 783 can extendfor a majority of the length of the backing 101, while each of thediscrete contact regions of the groups of discrete contact regions 781and 782 extend for a distance of less than the total length of thebacking 101.

FIG. 7C further includes an illustration of shaped abrasive particlesplaced on each of the groups of discrete contact regions 781, 782, and783. That is, the abrasive article can have a first group of shapedabrasive particles 784 associated with the first group of discretecontact regions 781, and a second group of shaped abrasive particles 785can be associated with the second group of discrete containment regions782, and a third group of shaped abrasive particles 792 can beassociated with the third group of discrete containment regions 789.

FIG. 7D includes an image of a portion of a group of shaped abrasiveparticles associated with a discrete contact region. Notably, the firstgroup of shaped abrasive particles 787 can include a first shapedabrasive particle 788 coupled to the backing 101 in a first position 795and a second shaped abrasive particle 789 coupled to the backing 101 ina second position 796. According to certain embodiments, the firstshaped abrasive particle 788 and second shaped abrasive particle 789 canbe arranged in a controlled, non-shadowing arrangement. In thecontrolled, non-shadowing arrangement, the first shaped abrasiveparticle 788 and second shaped abrasive particle 789 can have at leasttwo of a predetermined rotational orientation, a predetermined lateralorientation, and a predetermined longitudinal orientation, and acombination thereof. More particularly, at least a portion of the firstshaped abrasive particle 788 can be touching a portion of the secondshaped abrasive particle 789. Unlike some other embodiments herein, incertain instances, the shaped abrasive particles within a group can beabutting each other. For example, in at least one embodiment, a cornerof the first shaped abrasive particle 788 can be abutting a corner ofthe second shaped abrasive particle 789. Notably, the degree of overlapbetween adjacent particles can be less than the width of the particles,and more particularly, less than half of the width of the particles.

In the illustrated embodiment of FIG. 7D, at least a portion, such as aminority or majority, of each of the shaped abrasive particles of thefirst group of shaped abrasive particles 787 including the first shapedabrasive particle 788 and the second shaped abrasive particle 789 can bearranged in a line with respect to each other. Moreover, at least aportion of the shaped abrasive particles in the group of shaped abrasiveparticles 787 can be touching at least one other, immediately adjacent,shaped abrasive particle. Without wishing to be tied to a particulartheory, it is thought that some contact between the abrasive particles,may be suitable to buttress the group of shaped abrasive particles andimprove grain retention and grinding performance. Moreover, one or moreshaped abrasive particles in a group of shaped abrasive particles may bein direct contact with immediately adjacent grains to facilitate highergrain weights and improved grinding performance in certain applications.

Methods and Systems for Forming Abrasive Articles

The foregoing has described abrasive articles of the embodiments havingpredetermined distributions of shaped abrasive particles. The followingdescribes various methods used to form such abrasive articles of theembodiments herein. It will be appreciated that any of the methods andsystems described herein can be used in combination to facilitate theformation of an abrasive article according to an embodiment.

According to one embodiment, a method of forming an abrasive articleincludes placing a shaped abrasive particle on the backing in a firstposition defined by one or more predetermined orientationcharacteristics. In particular, the method of placing the shapedabrasive particle can include a templating process. A templating processmay make use of an alignment structure, which may be configured to hold(temporarily or permanently) one or more shaped abrasive particles in apredetermined orientation and deliver the one or more shaped abrasiveparticles onto the abrasive article in a predetermined position definedhaving one or more predetermined orientation characteristics.

According to one embodiment, the alignment structure can be variousstructures, including but not limited to, a web, a fibrous material, amesh, a solid structure having openings, a belt, a roller, a patternedmaterial, a discontinuous layer of material, a patterned adhesivematerial, and a combination thereof. In one particular embodiment, thealignment structure can include a discrete contact region configured tohold a shaped abrasive particle. In certain other instances, thealignment structure can include a plurality of discrete contact regionsspaced apart from each other and configured to hold a plurality ofshaped abrasive particles. For certain embodiments herein, a discretecontact region can be configured to temporarily hold a shaped abrasiveparticle and place the first shaped abrasive particle at a predeterminedposition on the abrasive article. Alternatively, in another embodiment,the discrete contact region can be configured to permanently hold afirst shaped abrasive particle and place the first shaped abrasiveparticle at the first position. Notably, for embodiments utilizing apermanent hold between the discrete contact region and the shapedabrasive particle, the alignment structure may be integrated within thefinished abrasive article.

Some exemplary alignments structures according to embodiments herein areillustrated in FIGS. 9-11. FIG. 9 includes an illustration of a portionof an alignment structure according to an embodiment. In particular, thealignment structure 900 can be in the form of web or mesh includingfibers 901 and 902 overlapping each other. In particular, the alignmentstructure 900 can include discrete contact regions 904, 905, and 906,which may be defined by a plurality of intersections of objects of thealignment structure. In the particular illustrated embodiment, thediscrete contact regions 904-906 can be defined by an intersection ofthe fibers 901 and 902, and more particularly, a joint between the twofibers 901 and 902, configured to hold the shaped abrasive particles911, 912, and 913. According to certain embodiments, the alignmentstructure can further include discrete contact regions 904-906 that caninclude an adhesive material to facilitate placement and holding of theshaped abrasive particles 911-913.

As will be appreciated, the construction and arrangement of the fibers901 and 902 can facilitate control of the discrete contact regions904-906 and further can facilitate control of one or more predeterminedorientation characteristics of the shaped abrasive particles on theabrasive article. For example, the discrete contact regions 904-906 canbe configured to define at least one of a predetermined rotationalorientation of a shaped abrasive particle, a predetermined rotationalorientation difference between at least two shaped abrasive particles, apredetermined longitudinal orientation of a shaped abrasive particle, alongitudinal space between two shaped abrasive particles, apredetermined lateral orientation, a lateral space between two shapedabrasive particles, a predetermined vertical orientation of a shapedabrasive particle, a predetermined vertical orientation differencebetween two shaped abrasive particles, a predetermined tip heightorientation of a shaped abrasive particle, a predetermined tip heightdifference between two shaped abrasive particles, and a combinationthereof.

FIG. 10 includes an illustration of a portion of an alignment structureaccording to an embodiment. In particular, the alignment structure 1000can be in the form of a belt 1001 having discrete contact regions 1002and 1003 configured to engage and hold the shaped abrasive particles1011 and 1012. According to an embodiment, the alignment structure 1000can include discrete contact regions 1002 and 1003 in the form ofopenings in the alignment structure. Each of the openings can a shapeconfigured to hold one or more shaped abrasive particles. Notably, eachof the openings can have a shape configured to hold one or more shapedabrasive particles in a predetermined position to facilitate placementof the one or more shaped abrasive particles on the backing in apredetermined position with one or more predetermined orientationcharacteristics. In at least one embodiment, the openings defining thediscrete contact regions 1002 and 1003 can have a cross-sectional shapecomplementary to a cross-sectional shape of the shaped abrasiveparticles. Moreover, in certain instances, the openings defining thediscrete contact regions can extend through an entire thickness of thealignment structure (i.e., belt 1001).

In yet another embodiment, the alignment structure can include discretecontact regions defined by openings, wherein the openings extendpartially through the entire thickness of the alignment structure. Forexample, FIG. 11 includes an illustration of a portion of an alignmentstructure according to an embodiment. Notably, the alignment structure1100 can be in the form of a thicker structure wherein the openingsdefining the discrete contact regions 1102 and 1103 configured to holdthe shaped abrasive particles 1111 and 1112 do not extend through theentire thickness of the substrate 1101.

FIG. 12 includes an illustration of a portion of an alignment structureaccording to an embodiment. Notably, the alignment structure 1200 can bein the form of a roller 1201 having openings 1203 in the exteriorsurface and defining the discrete contact regions. The discrete contactregions 1203 can have particular dimensions configured to facilitateholding of the shaped abrasive particles 1204 in the roller 1201 until aportion of the shaped abrasive particles are contacted to the abrasivearticle 1201. Upon contact with the abrasive article 1201, the shapedabrasive particles 1204 can be released from the roller 1201 anddelivered to the abrasive article 1201 in a particular position definedby one or more predetermined orientation characteristics. Accordingly,the shape and orientation of the openings 1203 on the roller 1201, theposition of the roller 1201 relative to the abrasive article 1201, therate of translation of the roller 1201 relative to the abrasive article1201 may be controlled to facilitate positioning of the shaped abrasiveparticles 1204 in a predetermined distribution.

Various processing steps may be utilized to facilitate the placement ofthe shaped abrasive particles on the alignment structure. Suitableprocesses can include, but are not limited to, vibration, adhesion,electromagnetic attraction, patterning, printing, pressure differential,roll coat, gravity drop, and a combination thereof. Moreover, particulardevices may be used to facilitate orientation of the shaped abrasiveparticles on the alignment structure, including for example, cams,acoustics, and a combination thereof.

In yet another embodiment, the alignment structure can be in the form ofa layer of adhesive material. Notably, the alignment structure can be inthe form of a discontinuous layer of adhesive portions, wherein theadhesive portions define discrete contact regions configured to hold(temporarily or permanently) one or more shaped abrasive particles.According to one embodiment, the discrete contact regions can include anadhesive, and more particularly, the discrete contact regions aredefined by a layer of adhesive, and still more particularly, each of thediscrete contact regions are defined by a discrete adhesive region. Incertain instances, the adhesive can include a resin, and moreparticularly, can include a material for use as a make coat as describedin embodiments herein. Moreover, the discrete contact regions can definea predetermined distribution relative to each other, and can furtherdefine positions of the shaped abrasive particles on the abrasivearticle. Furthermore, the discrete contact regions comprising theadhesive can be arranged in a predetermined distribution, which issubstantially the same as a predetermined distribution of shapedabrasive particles overlying the backing. In one particular instance,the discrete contact regions comprising the adhesive can be arranged ina predetermined distribution, can be configured to hold a shapedabrasive particle, and further can define at least one of apredetermined orientation characteristic for each shaped abrasiveparticle.

FIG. 13 includes an illustration of a portion of an alignment structureincluding discrete contact regions comprising an adhesive in accordancewith an embodiment. As illustrated, the alignment structure 1300 caninclude a first discrete contact region 1301 comprising a discreteregion of adhesive and configured to couple a shaped abrasive particle.The alignment structure 1300 can also include a second discrete contactregion 1302 and a third discrete contact region 1303. According to oneembodiment, at least the first discrete contact region 1301 can have awidth (w) 1304 related to at least one dimension of the shaped abrasiveparticle, which may facilitate positioning of the shaped abrasiveparticle in a particular orientation relative to the backing. Forexample, certain suitable orientations relative to the backing caninclude a side orientation, a flat orientation, and invertedorientation. According to a particular embodiment, the first discretecontact region 1301 can have a width (w) 1304 related to a height (h) ofthe shaped abrasive particle to facilitate a side orientation of theshaped abrasive particle. It will be appreciated that reference hereinto a height can be reference to an average height or median height of asuitable sample size of a batch of shaped abrasive particles. Forexample, the width 1304 of the first discrete contact region 1301 can benot greater than the height of the shaped abrasive particle. In otherinstances, the width 1304 of the first discrete contact region 1301 canbe not greater than about 0.99(h), such as not greater than about0.95(h), not greater than about 0.9(h), not greater than about 0.85(h),not greater than about 0.8(h), not greater than about 0.75(h), or evennot greater than about 0.5(h). Still, in one non-limiting embodiment,the width 1304 of the first discrete contact region 1301 can be at leastabout 0.1(h), at least about 0.3(h), or even at least about 0.5(h). Itwill be appreciated that the width 1304 of the first discrete contactregion 1301 can be within a range between any of the minimum and maximumvalues noted above.

In accordance with a particular embodiment, the first discrete contactregion 1301 can be spaced apart from the second discrete contact region1302 via a longitudinal gap 1305, which is a measure of the shortestdistance between immediately adjacent discrete contact regions 1301 and1302 in a direction parallel to the longitudinal axis 180 of the backing101. In particular, control of the longitudinal gap 1305 may facilitatecontrol of the predetermined distribution of the shaped abrasiveparticles on the surface of the abrasive article, which may facilitateimproved performance. According to one embodiment, the longitudinal gap1305 can be related to a dimension of one or a sampling of shapedabrasive particle. For example, the longitudinal gap 1305 can be atleast equal to a width (w) of a shaped abrasive particle, wherein thewidth is a measure of the longest side of the particle as describedherein. It will be appreciated that reference herein to a width (w) ofthe shaped abrasive particle can be reference to an average width ormedian width of a suitable sample size of a batch of shaped abrasiveparticles. In a particular instance, the longitudinal gap 1305 can begreater than the width, such as at least about 1.1(w), at least about1.2 (w), at least about 1.5(w), at least about 2(w), at least about2.5(w), at least about 3(w) or even at least about 4(w). Still, in onenon-limiting embodiment, the longitudinal gap 1305 can be not greaterthan about 10(w), not greater than about 9(w), not greater than about8(w), or even not greater than about 5(w). It will be appreciated thatthe longitudinal gap 1305 can be within a range between any of theminimum and maximum values noted above.

In accordance with a particular embodiment, the second discrete contactregion 1302 can be spaced apart from the third discrete contact region1303 via a lateral gap 1306, which is a measure of the shortest distancebetween immediately adjacent discrete contact regions 1302 and 1303 in adirection parallel to the lateral axis 181 of the backing 101. Inparticular, control of the lateral gap 1306 may facilitate control ofthe predetermined distribution of the shaped abrasive particles on thesurface of the abrasive article, which may facilitate improvedperformance. According to one embodiment, the lateral gap 1306 can berelated to a dimension of one or a sampling of shaped abrasive particle.For example, the lateral gap 1306 can be at least equal to a width (w)of a shaped abrasive particle, wherein the width is a measure of thelongest side of the particle as described herein. It will be appreciatedthat reference herein to a width (w) of the shaped abrasive particle canbe reference to an average width or median width of a suitable samplesize of a batch of shaped abrasive particles. In a particular instance,the lateral gap 1306 can be less than the width of the shaped abrasiveparticle. Still, in other instances, the lateral gap 1306 can be greaterthan the width of the shaped abrasive particle. According to one aspect,the lateral gap 1306 can be zero. In yet another aspect, the lateral gap1306 can be at least about 0.1(w), at least about 0.5 (w), at leastabout 0.8(w), at least about 1(w), at least about 2 (w), at least about3(w) or even at least about 4(w). Still, in one non-limiting embodiment,the lateral gap 1306 may be not greater than about 100(w), not greaterthan about 50(w), not greater than about 20(w), or even not greater thanabout 10(w). It will be appreciated that the lateral gap 1306 can bewithin a range between any of the minimum and maximum values notedabove.

The first discrete contact region 1301 can be formed on an upper majorsurface of a backing using various methods, including for example,printing, patterning, gravure rolling, etching, removing, coating,depositing, and a combination thereof. FIGS. 14A-14H include top downviews of portions of tools for forming abrasive articles having variouspatterned alignment structures including discrete contact regions of anadhesive material according to embodiments herein. In particularinstances, the tools can include a templating structure that can becontacted to the backing and transfer the patterned alignment structureto the backing. In one particular embodiment, the tool can be a gravureroller having a patterned alignment structure comprising discretecontact regions of adhesive material that can be rolled over a backingto transfer the patterned alignment structure to the backing. Afterwhich, shaped abrasive particles can be placed on the backing in theregions corresponding to the discrete contact regions.

In at least one particular aspect, an abrasive article of an embodimentcan including forming a patterned structure comprising an adhesive on atleast a portion of the backing. Notably, in one instance, the patternedstructure can be in the form of a patterned make coat. The patternedmake coat can be a discontinuous layer including at least one adhesiveregion overlying the backing, a second adhesive region overlying thebacking separate from the first adhesive region, and at least oneexposed region between the first and second adhesive regions. The atleast one exposed region can be essentially free of adhesive materialand represent a gap in the make coat. In one embodiment, the patternedmake coat can be in the form of an array of adhesive regions coordinatedrelative to each other in a predetermined distribution. The formation ofthe patterned make coat with a predetermined distribution of adhesiveregions on the backing can facilitate placement of the shaped abrasivegrains in a predetermined distribution, and particularly, thepredetermined distribution of the adhesive regions of the patterned makecoat can correspond to the positions of the shaped abrasive particles,wherein each of the shaped abrasive particles can be adhered to thebacking at the adhesive regions, and thus correspond to thepredetermined distribution of shaped abrasive particles on the backing.Moreover, in at least one embodiment, essentially no shaped abrasiveparticles of the plurality of shaped abrasive particles are overlyingthe exposed regions. Furthermore, it will be appreciated that a singleadhesive region can be shaped and sized to accommodate a single shapedabrasive particle. However, in an alternative embodiment, an adhesiveregion can be shaped and sized to accommodate a plurality of shapedabrasive particles.

Various processes may be utilized in the formation of a patternedstructure, including for example, a patterned make coat. In oneembodiment, the process can include selectively depositing the makecoat. In yet another embodiment, the process can include selectivelyremoving at least a portion of the make coat. Some exemplary processescan include coating, spraying, rolling, printing, masking, irradiating,etching, and a combination thereof. According to a particularembodiment, forming the patterned make coat can include providing apatterned make coat on a first structure and transferring the patternedmake coat to at least a portion of the backing. For example, a gravureroller may be provided with a patterned make coat layer, and the rollercan be translated over at least a portion of the backing andtransferring the patterned make coat from the roller surface to thesurface of the backing.

The foregoing has described particular abrasive articles and structures(e.g., alignment structures) suitable for use in forming the abrasivearticles. The following embodiments describe particular methods, whichmay be used in conjunction with the embodiments herein or separately,that facilitate the formation of abrasive articles according toembodiments.

In accordance with one embodiment, the process of delivering the shapedabrasive particles to the abrasive article can include expelling thefirst shaped abrasive particle from an opening within the alignmentstructure. Some suitable exemplary methods for expelling can includeapplying a force on the shaped abrasive particle and removing it fromthe alignment structure. For example, in certain instances, the shapedabrasive particle can be contained in the alignment structure andexpelled from the alignment structure using gravity, electrostaticattraction, surface tension, pressure differential, mechanical force,magnetic force, agitation, vibration, and a combination thereof. In atleast one embodiment, the shaped abrasive particles can be contained inthe alignment structure until a surface of the shaped abrasive particlesare contacted to a surface of the backing, which may include an adhesivematerial, and the shaped abrasive particles are removed from thealignment structure and delivered to a predetermined position on thebacking.

According to another aspect, the shaped abrasive particles can bedelivered to the surface of the abrasive article in a controlled mannerby sliding the shaped abrasive particles along a pathway. For example,in one embodiment, the shaped abrasive particles can be delivered to apredetermined position on the backing by sliding the abrasive particlesdown a pathway and through an opening via gravity. FIG. 15 includes anillustration of a system according to an embodiment. Notably, the system1500 can include a hopper 1502 configured to contain a content of shapedabrasive particles 1503 and deliver the shaped abrasive particles 1503to a surface of a backing 1501 that can be translated under the hopper1502. As illustrated, the shaped abrasive particles 1503 can bedelivered down a pathway 1504 attached to the hopper 1502 and deliveredto a surface of the backing 1501 in a controlled manner to form a coatedabrasive article including shaped abrasive particles arranged in apredetermined distribution relative to each other. In particularinstances, the pathway 1504 can be sized and shaped to deliver aparticular number of shaped abrasive particles at a particular rate tofacilitate the formation of the predetermined distribution of shapedabrasive particles. Furthermore, the hopper 1502 and the pathway 1504may be movable relative to the backing 1501 to facilitate the formationof select predetermined distributions of shaped abrasive particles.

Moreover, the backing 1501 may further be translated over a vibratingtable 1506 that can agitate or vibrate the backing 1501 and the shapedabrasive particles contained on the backing 1501 to facilitate improvedorientation of the shaped abrasive particles.

In yet another embodiment, the shaped abrasive particles can bedelivered to a predetermined position by expelling individual shapedabrasive particles on to the backing via a throwing process. In thethrowing process, shaped abrasive particles may be accelerate andexpelled from a container at a rate sufficient to hold the abrasiveparticles at a predetermined position on the backing. For example, FIG.16 includes an illustration of a system using a throwing process,wherein shaped abrasive particles 1602 are expelled from a throwing unit1603 that can accelerate the shaped abrasive particles via a force(e.g., pressure differential) and deliver the shaped abrasive particles1602 from the throwing unit 1603 down a pathway 1605, which may beattached to the throwing unit 1603 and onto a backing 1601 in apredetermined position. The backing 1601 may be translated under thethrowing unit 1603, such that after initial placement, the shapedabrasive particles 1602 can undergo a curing process that may cure anadhesive material on the surface of the backing 1601 and hold the shapedabrasive particles 1602 in their predetermined positions.

FIG. 17A includes an illustration of an alternative throwing process inaccordance with an embodiment. Notably, the throwing process can includeexpelling a shaped abrasive particle 1702 from a throwing unit 1703 overa gap 1708 to facilitate placement of the shaped abrasive particle 1702on the backing in a predetermined position. It will be appreciated thatthe force of expelling, the orientation of the shaped abrasive particle1702 upon being expelled, the orientation of the throwing unit 1703relative the backing 1701, and the gap 1708 may be controlled andadjusted to adjust the predetermined position of the shaped abrasiveparticle 1702 and the predetermined distribution of shaped abrasiveparticles 1702 on the backing 1701 relative to each other. It will beappreciated that the abrasive article 1701 may include an adhesivematerial 1712 on a portion of the surface to facilitate adherencebetween the shaped abrasive particles 1702 and the abrasive article1701.

In particular instances, the shaped abrasive particles 1702 can beformed to have a coating. The coating can be overlying at least portionof the exterior surface of the shaped abrasive particles 1702. In oneparticular embodiment, the coating can include an organic material, andmore particularly, a polymer, and still more particularly an adhesivematerial. The coating comprising an adhesive material may facilitateattachment of the shaped abrasive particles 1702 to the backing 1701.

FIG. 17B includes an illustration of an alternative throwing process inaccordance with an embodiment. In particular, the embodiment of FIG. 17Bdetails a particular throwing unit 1721 configured to direct the shapedabrasive particles 1702 at the abrasive article 1701. According to anembodiment, the throwing unit 1721 can include a hopper 1723 configuredto contain a plurality of shaped abrasive particles 1702. Furthermore,the hopper 1723 can be configured to deliver one or more shaped abrasiveparticles 1702 in a controlled manner to an acceleration zone 1725,wherein the shaped abrasive particles 1702 are accelerated and directedtoward the abrasive article 1701. In one particular embodiment, thethrowing unit 1721 can include a system 1722 utilizing a pressurizedfluid, such as a controlled gas stream or air knife unit, to facilitatethe acceleration of the shaped abrasive particles 1702 in theacceleration zone 1725. As further illustrated, the throwing unit 1721may utilize a slide 1726 configured to generally direct the shapedabrasive particles 1702 toward the abrasive article 1701. In oneembodiment, the throwing unit 1731 and/or the slide 1726 can be moveablebetween a plurality of positions and configured to facilitate deliveryof individual shaped abrasive particles to particular positions on theabrasive article, thus facilitating the formation of the predetermineddistribution of shaped abrasive particles.

FIG. 17A includes an illustration of an alternative throwing process inaccordance with an embodiment. In the illustrated embodiment of FIG. 17Cdetails an alternative throwing unit 1731 configured to direct theshaped abrasive particles 1702 at the abrasive article 1701. Accordingto an embodiment, the throwing unit 1731 can include a hopper 1734configured to contain a plurality of shaped abrasive particles 1702 anddeliver one or more shaped abrasive particles 1702 in a controlledmanner to an acceleration zone 1735, wherein the shaped abrasiveparticles 1702 are accelerated and directed toward the abrasive article1701. In one particular embodiment, the throwing unit 1731 can include aspindle 1732 that may be rotated around an axis and configured to rotatea stage 1733 at a particular rate of revolutions. The shaped abrasiveparticles 1702 can be delivered from the hopper 1734 to the stage 1733and accelerated at a particular from the stage 1733 toward the abrasivearticle 1701. As will be appreciated, the rate of rotation of thespindle 1732 may be controlled to control the predetermined distributionof shaped abrasive particles 1702 on the abrasive article 1701.Furthermore, the throwing unit 1731 can be moveable between a pluralityof positions and configured to facilitate delivery of individual shapedabrasive particles to particular positions on the abrasive article, thusfacilitating the formation of the predetermined distribution of shapedabrasive particles.

According to another embodiment, the process of delivering the shapedabrasive particles in a predetermined position on the abrasive articleand forming an abrasive article having a plurality of shaped abrasiveparticles in a predetermined distribution relative to each other caninclude the application of magnetic force. FIG. 18 includes anillustration of a system according to an embodiment. The system 1800 caninclude a hopper 1801 configured to contain a plurality of shapedabrasive particles 1802 and deliver the shaped abrasive particles 1802to a first translating belt 1803.

As illustrated, the shaped abrasive particles 1802 can be translatedalong the belt 1803 to an alignment structure 1805 configured to containeach of the shaped abrasive particles at a discrete contact region.According to one embodiment, the shaped abrasive particles 1802 can betransferred from the belt 1803 to the alignment structure 1805 via atransfer roller 1804. In particular instances, the transfer roller 1804may utilize a magnet to facilitate controlled removal of the shapedabrasive particles 1802 from the belt 1803 to the alignment structure1805. The provision of a coating comprising a magnetic material mayfacilitate the use of the transfer roller 1804 with magneticcapabilities.

The shaped abrasive particles 1802 and can be delivered from thealignment structure 1805 to a predetermined position on the backing1807. As illustrated, the backing 1807 may be translated on a separatebelt and from the alignment structure 1805 and contact the alignmentstructure to facilitate the transfer of the shaped abrasive particles1802 from the alignment structure 1805 to the backing 1807.

In still another embodiment, the process of delivering the shapedabrasive particles in a predetermined position on the abrasive articleand forming an abrasive article having a plurality of shaped abrasiveparticles in a predetermined distribution relative to each other caninclude the use of an array of magnets. FIG. 19 includes an illustrationof a system for forming an abrasive article according to an embodiment.In particular, the system 1900 can include shaped abrasive particles1902 contained within an alignment structure 1901. As illustrated, thesystem 1900 can include an array of magnets 1905, which can include aplurality of magnets arranged in a predetermined distribution relativeto the backing 1906. According to an embodiment, the array of magnets1905 can be arranged in a predetermined distribution that can besubstantially the same as the predetermined distribution of shapedabrasive particles on the backing.

Moreover, each of the magnets of the array of magnets 1905 can bemoveable between a first position and a second position, which canfacilitate control of the shape of the array of magnets 1905 and furtherfacilitate control of the predetermined distribution of the magnets andthe predetermined distribution of shaped abrasive particles 1902 on thebacking. According to one embodiment, the array of magnets 1905 can bechanged to facilitate control of one or more predetermined orientationcharacteristics of the shaped abrasive particles 1902 on the abrasivearticle.

Furthermore, each of the magnets of the array of magnets 1905 may beoperable between a first state and a second state, wherein a first statecan be associated with a first magnetic strength (e.g., an on state) andthe second state can be associated with a second magnetic strength(e.g., an off state). Control of the state of each of the magnets canfacilitate selective delivery of shaped abrasive particles to particularregions of the backing 1906 and further facilitate control of thepredetermined distribution. According to one embodiment, the state ofthe magnets of the array of magnets 1905 can be changed to facilitatecontrol of one or more predetermined orientation characteristics of theshaped abrasive particles 1902 on the abrasive article.

FIG. 20A includes an image of a tool used to form an abrasive article inaccordance with an embodiment. Notably, the tool 2051 can include asubstrate, which may be an alignment structure having openings 2052defining discrete contact regions configured to contain shaped abrasiveparticles and assist in the transfer and placement of shaped abrasiveparticles on a finally-formed abrasive article. As illustrated, theopenings 2052 can be arranged in a predetermined distribution relativeto each other on alignment structure. In particular, the openings 2052can be arranged in one or more groups 2053 having a predetermineddistribution relative to each other, which can facilitate the placementof the shaped abrasive particles on the abrasive article in apredetermined distribution defined by one or more predeterminedorientation characteristics. In particular, the tool 2051 can include agroup 2053 defined by a row of openings 2052. Alternatively, the tool2051 may have a group 2055 defined by all of the openings 2052illustrated, since each of the openings have substantially the samepredetermined rotational orientation relative to the substrate.

FIG. 20B includes an image of a tool used to form an abrasive articleaccording to an embodiment. Notably, as illustrated in FIG. 20B, shapedabrasive particles 2001 are contained in the tool 2051 of FIG. 20A, andmore particularly, the tool 2051 can be an alignment structure, whereineach of the openings 2052 contains a single shaped abrasive particle2001. In particular, the shaped abrasive particles 2001 can have atriangular two-dimensional shaped, as viewed top-down. Moreover, theshaped abrasive particles 2001 can be placed into the openings 2052 suchthat a tip of the shaped abrasive particle extends into and through theopenings 2052 to the opposite side of the tool 2051. The openings 2052can be sized and shaped such that they substantially complement at leasta portion (if not the entire) contour of the shaped abrasive particles2001 and hold them in a position defined by one or more predeterminedorientation characteristics in the tool 2051, which will facilitatetransfer of the shaped abrasive particles 2001 from the tool 2051 to abacking while maintaining the predetermined orientation characteristics.As illustrated, the shaped abrasive particles 2001 can be containedwithin the openings 2052 such that at least a portion of the surfaces ofthe shaped abrasive particles 2001 extends above the surface of the tool2051, which may facilitate transfer of the shaped abrasive particles2001 from the openings 2052 to a backing.

As illustrated, the shaped abrasive particles 2001 can define a group2002. The group 2002 can have a predetermined distribution of shapedabrasive particles 2001, wherein each of the shaped abrasive particleshas substantially the same predetermined rotational orientation.Moreover, each of the shaped abrasive particles 2001 has substantiallythe same predetermined vertical orientation and predetermined tip heightorientation. Furthermore, the group 2002 includes multiple rows (e.g.,2005, 2006, and 2007) oriented in a plane parallel to a lateral axis2081 of the tool 2051. Moreover, within the group 2002, smaller groups(e.g., 2012, 2013, and 2014) of the shaped abrasive particles 2001 mayexist, wherein the shaped abrasive particles 2001 share a samedifference in a combination of a predetermined lateral orientation andpredetermined longitudinal orientation relative to each other. Notably,the shaped abrasive particle 2001 of the groups 2012, 2013, and 2014 canbe oriented in raked columns, wherein the group extends at an angle tothe longitudinal axis 2080 of the tool 2051, however, the shapedabrasive particles 2001 can have substantially a same difference in thepredetermined longitudinal orientation and predetermined lateralorientation relative to each other. As also illustrated, thepredetermined distribution of shaped abrasive particles 2001 can definesa pattern, which may be considered a triangular pattern 2011. Moreover,the group 2002 can be arranged such that the boundary of the groupdefines a two-dimensional microunit of a quadrilateral (see dottedline).

FIG. 20C includes an image of a portion of an abrasive article accordingto an embodiment. In particular, the abrasive article 2060 includes abacking 2061 and a plurality of shaped abrasive particles 2001, whichwere transferred from the openings 2052 of the tool 2051 to the backing2061. As illustrated, the predetermined distribution of the openings2052 of the tool can correspond to the predetermined distribution ofshaped abrasive particles 2001 of the group 2062 contained on thebacking 2061. The predetermined distribution of shaped abrasiveparticles 2001 can be defined by one or more predetermined orientationcharacteristics. Moreover, as evidence from FIG. 20C, the shapedabrasive particles 2001 can be arranged in groups that substantiallycorrespond to the groups of the shaped abrasive particles of FIG. 20B,when the shaped abrasive particles 2001 were contained in the tool 2051.

For certain abrasive articles herein, at least about 75% of theplurality of shaped abrasive particles on the abrasive article can havea predetermined orientation relative to the backing, including forexample a side orientation as described in embodiments herein. Still,the percentage may be greater, such as at least about 77%, at leastabout 80%, at least about 81%, or even at least about 82%. And for onenon-limiting embodiment, an abrasive article may be formed using theshaped abrasive particles herein, wherein not greater than about 99% ofthe total content of shaped abrasive particles have a predetermined sideorientation. It will be appreciated that reference herein to percentagesof shaped abrasive particles in a predetermined orientation is basedupon a statistically relevant number of shaped abrasive particles and arandom sampling of the total content of shaped abrasive particles.

To determine the percentage of particles in a predetermined orientation,a 2D microfocus x-ray image of the abrasive article is obtained using aCT scan machine run in the conditions of Table 1 below. The X-ray 2Dimaging was conducted using Quality Assurance software. A specimenmounting fixture utilizes a plastic frame with a 4″×4″ window and an00.5″ solid metallic rod, the top part of which is half flattened withtwo screws to fix the frame. Prior to imaging, a specimen was clippedover one side of the frame where the screw heads were faced with theincidence direction of the X-rays. Then five regions within the 4″×4″window area are selected for imaging at 120 kV/80 pA. Each 2D projectionwas recorded with the X-ray off-set/gain corrections and at amagnification

TABLE 1 Field of view Current per image Voltage (kV) (μA) Magnification(mm × mm) Exposure time 120 80 15X 16.2 × 13.0 500 ms/2.0 fps

The image is then imported and analyzed using the ImageJ program,wherein different orientations are assigned values according to Table 2below. FIG. 32 includes images representative of portions of a coatedabrasive according to an embodiment and used to analyze the orientationof shaped abrasive particles on the backing.

TABLE 2 Cell marker type Comments 1 Grains on the perimeter of theimage, partially exposed - standing in a side orientation (e.g.,particles standing on their side surface) 2 Grains on the perimeter ofthe image, partially exposed - down orientation (i.e., particles in aflat orientation or inverted orientation) 3 Grains on the image,completely exposed - standing in a side orientation 4 Grains on theimage, completely exposed - down 5 Grains on the image, completelyexposed - standing slanted (between standing vertical and down at a 45degree angle)

Three calculations are then performed as provided below in Table 3.After conducting the calculations the percentage of shaped abrasiveparticles in a side orientation per square centimeter can be derived.Notably, a particle having a side orientation is a particle having avertical orientation, as defined by the angle between a major surface ofthe shaped abrasive particle and the surface of the backing, wherein theangle is 45 degrees or greater. Accordingly, a shaped abrasive particlehaving an angle of 45 degrees or greater is considered standing orhaving a side orientation, a shaped abrasive particle having an angle of45 degrees is considered standing slanted, and a shaped abrasiveparticle having an angle of less than 45 degrees is considered having adown orientation.

TABLE 3 Parameter Protocol* % grains up ((0.5 × 1) + 3 + 5)/(1 + 2 + 3 +4 + 5) Total # of grains per cm² (1 + 2 + 3 + 4 + 5) # of grains up percm² (% grains up × Total # of grains per cm² *These are all normalizedwith respect to the representative area of the image. + - A scale factorof 0.5 was applied to account for the fact that they are not completelypresent in the image.

Furthermore, the abrasive articles made with the shaped abrasiveparticles can utilize various contents of the shaped abrasive particles.For example, the abrasive articles can be coated abrasive articlesincluding a single layer of the shaped abrasive particles in anopen-coat configuration or a closed coat configuration. However, it hasbeen discovered, quite unexpectedly, that the shaped abrasive particlesdemonstrate superior results in an open coat configuration. For example,the plurality of shaped abrasive particles can define an open coatabrasive product having a coating density of shaped abrasive particlesof not greater than about 70 particles/cm². In other instances, thedensity of shaped abrasive particle per square centimeter of theabrasive article may be not greater than about 65 particles/cm², such asnot greater than about 60 particles/cm², not greater than about 55particles/cm², or even not greater than about 50 particles/cm². Still,in one non-limiting embodiment, the density of the open coat coatedabrasive using the shaped abrasive particle herein can be at least about5 particles/cm², or even at least about 10 particles/cm². It will beappreciated that the density of shaped abrasive particles per squarecentimeter of abrasive article can be within a range between any of theabove minimum and maximum values.

In certain instances, the abrasive article can have an open coat densityof a coating not greater than about 50% of abrasive particle coveringthe exterior abrasive surface of the article. In other embodiments, thepercentage coating of the abrasive particles relative to the total areaof the abrasive surface can be not greater than about 40%, not greaterthan about 30%, not greater than about 25%, or even not greater thanabout 20%. Still, in one non-limiting embodiment, the percentage coatingof the abrasive particles relative to the total area of the abrasivesurface can be at least about 5%, such as at least about 10%, at leastabout 15%, at least about 20%, at least about 25%, at least about 30%,at least about 35%, or even at least about 40%. It will be appreciatedthat the percent coverage of shaped abrasive particles for the totalarea of abrasive surface can be within a range between any of the aboveminimum and maximum values.

Some abrasive articles may have a particular content of abrasiveparticles for a length (e.g., ream) of the backing. For example, in oneembodiment, the abrasive article may utilize a normalized weight ofshaped abrasive particles of at least about 10 lbs/ream (148 grams/m²),at least about 15 lbs/ream, at least about 20 lbs/ream, such as at leastabout 25 lbs/ream, or even at least about 30 lbs/ream. Still, in onenon-limiting embodiment, the abrasive articles can include a normalizedweight of shaped abrasive particles of not greater than about 60lbs/ream (890 grams/m²), such as not greater than about 50 lbs/ream, oreven not greater than about 45 lbs/ream.

It will be appreciated that the abrasive articles of the embodimentsherein can utilize a normalized weight of shaped abrasive particlewithin a range between any of the above minimum and maximum values.

In certain instances, the abrasive articles can be used on particularworkpieces. A suitable exemplary workpiece can include an inorganicmaterial, an organic material, a natural material, and a combinationthereof. According to a particular embodiment, the workpiece can includea metal or metal alloy, such as an iron-based material, a nickel-basedmaterial, and the like. In one embodiment, the workpiece can be steel,and more particularly, can consist essentially of stainless steel (e.g.,304 stainless steel).

Example 1

A grinding test is conducted to evaluate the effect of orientation of ashaped abrasive grain relative to a grinding direction. In the test, afirst set of shaped abrasive particles (Sample A) are oriented infrontal orientation relative to the grinding direction. Turning brieflyto FIG. 3B, the shaped abrasive particle 102 has a frontal orientationgrinding direction 385, such that the major surface 363 defines a planesubstantially perpendicular to the grinding direction, and moreparticularly, the bisecting axis 231 of the shaped abrasive particle 102is substantially perpendicular to the grinding direction 385. Sample Awas mounted on a holder in a frontal orientation relative to a workpieceof austenitic stainless steel. The wheel speed and work speed weremaintained at 22 m/s and 16 mm/s respectively. The depth of cut can beselected between 0 and 30 micron. Each test consisted of 15 passesacross the 8 inch long workpiece. For each test, 10 repeat samples wererun and the results were analyzed and averaged. The change in thecross-sectional area of the groove from beginning to the end of thescratch length was measured to determine the grit wear.

A second set of samples (Sample B) are also tested according to thegrinding test described above for Sample A. Notably, however, the shapedabrasive particles of Sample B have a sideways orientation on thebacking relative to the grinding direction. Turning briefly to FIG. 3B,the shaped abrasive particle 103 is illustrated as having a sidewaysorientation relative to the grinding direction 385. As illustrated, theshaped abrasive particle 103 can include major surfaces 391 and 392,which can be joined by side surfaces 371 and 372, and the shapedabrasive particle 103 can have a bisecting axis 373 forming a particularangle relative to the vector of the grinding direction 385. Asillustrated, the bisecting axis 373 of the shaped abrasive particle 103can have a substantially parallel orientation with the grindingdirection 385, such that the angle between the bisecting axis 373 andthe grinding direction 385 is essentially 0 degrees. Accordingly, thesideways orientation of the shaped abrasive particle 103 may facilitateinitial contact of the side surface 372 with a workpiece before any ofthe other surfaces of the shaped abrasive particle 103.

FIG. 21 includes a plot of normal force (N) versus cut number for SampleA and Sample B according to the grinding test of Example 1. FIG. 21illustrates the normal force necessary to conduct grinding of theworkpiece with the shaped abrasive particles of the representativesamples A and B for multiple passes or cuts. As illustrated, the normalforce of Sample A is initially lower than the normal force of Sample B.However, as the testing continues, the normal force of Sample A exceedsthe normal force of Sample B. Accordingly, in some instances an abrasivearticle may utilize a combination of different orientations (e.g.,frontal orientation and sideways orientation) of the shaped abrasiveparticles relative to an intended grinding direction to facilitateimproved grinding performance. In particular, as illustrated in FIG. 21,a combination of orientations of shaped abrasive particles relative to agrinding direction may facilitate lower normal forces throughout thelife of the abrasive article, improved grinding efficiency, and greateruseable life of the abrasive article. Thus, Example 1 demonstrates,among other things, that utilization of different groups of shapedabrasive particles having different predetermined orientationcharacteristics relative to each other and the grinding direction canfacilitate improved performance over patterns having conventionalpatterned grains.

Example 2

Five samples are analyzed to compare the orientation of shaped abrasiveparticles. Three samples (Samples S1, S2 and S3) are made according toan embodiment. FIG. 22 includes an image of a portion of Sample S1 usinga 2D microfocus X-ray via a CT scan machine according to the conditionsdescribed herein. Two other samples (Samples CS1 and CS2) arerepresentative of conventional abrasive products including shapedabrasive particles. Samples CS1 and CS2 are commercially available from3M as Cubitron II. Sample CS2 is commercially available from 3M asCubitron II. FIG. 23 includes an image of a portion of Sample CS2 using2D microfocus X-ray via a CT scan machine according to the conditionsdescribed herein. Each of the samples is evaluated according to theconditions described herein for evaluating the orientation of shapedabrasive particles via X-ray analysis.

FIG. 24 includes a plot of up grains/cm² and total number of grains/cm²for each of the samples (Sample 1 and Sample C1). As illustrated,Samples CS1 and CS2 demonstrate a significantly fewer number of shapedabrasive particles oriented in a side orientation (i.e., uprightorientation) as compared to Samples S1, S2, and S3. In particular,Sample S1 demonstrated all shaped abrasive particles (i.e., 100%)measured were oriented in a side orientation, while only 72 percent ofthe total number of shaped abrasive particles of CS2 had a sideorientation. As evidenced, state-of-the-art conventional abrasivearticles (C1) using shaped abrasive particles have not achieved theprecision of orientation of the presently described abrasive articles.

Example 3

Two samples were made and tested to analyze the effect of variousdistributions on grinding efficiency. A first sample (Sample S4) wasmade according to an embodiment having a non-shadowing distribution asdemonstrated by the pattern illustrated in FIG. 28. The arrangement ofthe shaped abrasive particles had a non-shadowing arrangement relativeto a grinding direction extending substantially parallel to the Y-axisof the plot and substantially parallel to a longitudinal axis of thebacking. Sample S4 used shaped abrasive particles having a triangulartwo-dimensional shape, approximately 20 lbs/ream of shaped abrasiveparticles, and at least 70% of the shaped abrasive particles wereoriented in a side orientation.

A second, conventional sample (Sample CS3) was made having aconventional pattern of shaped abrasive particles, which was an exampleof one type of shadowing distribution as demonstrated in FIG. 29, whichis an image of a portion of Sample CS3 demonstrating a square patternwherein the sides of the square repeating unit are aligned withlongitudinal and lateral axis of the backing The same size, shape, andamount of shaped abrasive particles used in Sample S4 were used inSample CS3, with the only substantial difference being the arrangementof shaped abrasive particles in the backing. As illustrated, thearrangement of shaped abrasive particles is a shadowing arrangementrelative to the lateral axis and longitudinal axis of the backing. Thegrinding direction was substantially parallel to the longitudinal axisof the backing.

The samples were tested under the conditions provided in Table 4 below.

TABLE 4 Material 4140 Carbon Steel Dimension 1″ square Force 40 psiProduct Speed 5000 sfm Machine: 122 Ds High Force Grinder (ConstantForce Belt Testor #4580)

The workpieces used for testing were analyzed using a Nanovea 3D OpticalProfilometer (white light chromatic aberration technique) to determinethe surface characteristics of the workpiece after the grindingoperation. For each workpiece tested, one area was profiled on eachsample using an area scan of 5.0 mm×5.0 mm. A step size of 10 μm wasused for both the X and Y axes for all samples. Unfiltered areaparameters (Sx) were calculated for the full scanned area. Twenty lineprofiles were extracted from the area scan and average parameters werecalculated (Px). All profile parameters reported in the sample data areexplained in specific detail in an additional slide for reference. Theanalysis enabled calculation of 6 surface characterizations as providedin Table 4 below. Note that Sa is the arithmetic mean deviation of thesurface according to the EUR 15178 EN Report (i.e., “The Development ofMethods for the Characterisation of Roughness in Three Dimensions,”Stout, K J., et al. Published on behalf of the Commission of theEuropean Communities). Sq is the root-mean-square deviation of thesurface according to EUR 15178 EN Report. St is the total height of thesurface and is a measure of the height difference between the highestpeak and deepest valley. Sp is the maximum height of the summits and isa measure of the height difference between the highest peak and the meanplane. Sv is the maximum depth of the valleys and is a measure of thedistance between the mean plane and the deepest valley. Sz is the tenpoint height of the surface and is the mean of distance between the fivehighest peaks and the 5 deepest valleys according to the EUR 15178 ENReport.

TABLE 5 Sample S4 Sample CS3 Sa 17.8 μm Sa 218 μm Sq 22.6 μm Sq 250 μmSz 176 μm Sz 1004 μm Sp 71.9 μm Sp 623 μm Sv 105 μm Sv 400 μm St 177 μmSt 1023 μm

FIG. 29 includes an image of a portion of the surface of the workpieceafter conducting the grinding operation with the abrasive of Sample S4.FIG. 30 includes an image of a portion of the surface of the workpieceafter conducting the grinding operation with the abrasive of Sample CS3.As clearly demonstrated in a comparison of the images and the data ofTable 5, the non-shadowing arrangement of shaped abrasive particlesassociated with Sample S4 resulted in significantly better grindingperformance and overall surface finish of the workpiece as compared tothe results obtained in the grinding operation using Sample CS3, whichutilized a shadowed pattern of shaped abrasive particles.

For each of the samples (i.e., S4 and CS3), three test runs werecompleted and the amount of material removed for each of the test runswas calculated and averaged. The average material removed for Sample S4was 16% greater as compared to Sample CS3, thus demonstrating improvedmaterial removal capabilities as compared to Sample CS3.

The present application represents a departure from the state of theart. While the industry has recognized that shaped abrasive particlesmay be formed through processes such as molding and screen printing, theprocesses of the embodiments herein are distinct from such processes.Notably, the embodiments herein include a combination of processfeatures facilitating the formation of batches of shaped abrasiveparticle having particular features. Moreover, the abrasive articles ofthe embodiments herein can have a particular combination of featuresdistinct from other abrasive articles including, but not limited to, apredetermined distribution of shaped abrasive particles, utilization ofa combination of predetermined orientation characteristics, groups,rows, columns, companies, micro-units, channel regions, aspects of theshaped abrasive particles, including but not limited to, aspect ratio,composition, additives, two-dimensional shape, three-dimensional shape,difference in height, difference in height profile, flashing percentage,height, dishing, and a combination thereof. And in fact, the abrasivearticles of embodiments herein may facilitate improved grindingperformance. While the industry has generally recognized that certainabrasive articles may be formed having an order to certain abrasiveunits, such abrasive units have traditionally been limited to abrasivecomposites that can be easily molded via a binder system, or usingtraditional abrasive or superabrasive grits. The industry has notcontemplated or developed systems for forming abrasive articles fromshaped abrasive particles having predetermined orientationcharacteristics as described herein. Manipulation of shaped abrasiveparticles in order to effectively control predetermined orientationcharacteristics is a non-trivial matter, having exponentially improvedcontrol of particles in three-space, which is not disclosed or suggestedin the art. Reference herein to the term “the same” will be understoodto mean substantially the same. Moreover, it will be appreciated thatwhile embodiments herein have referenced backings having a generallyrectangular shape, the arrangement of shaped abrasive particles in anon-shadowing arrangement can be equally applicable to other shapes ofbackings (e.g., round or ellipsoidal-shaped backings).

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true scope of the present invention. Thus, to the maximum extentallowed by law, the scope of the present invention is to be determinedby the broadest permissible interpretation of the following claims andtheir equivalents, and shall not be restricted or limited by theforegoing detailed description. The description of embodiments incombination with the figures is provided to assist in understanding theteachings disclosed herein and should not be interpreted as a limitationon the scope or applicability of the teachings. Other embodiments can beused based on the teachings as disclosed in this application.

The terms “comprises,” “comprising,” “includes,” “including,” “has,”“having” or any other variation thereof, are intended to cover anon-exclusive inclusion. For example, a method, article, or apparatusthat comprises a list of features is not necessarily limited only tothose features but may include other features not expressly listed orinherent to such method, article, or apparatus. Further, unlessexpressly stated to the contrary, “or” refers to an inclusive-or and notto an exclusive-or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or notpresent), A is false (or not present) and B is true (or present), andboth A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one, at least one, or the singular as alsoincluding the plural, or vice versa, unless it is clear that it is meantotherwise. For example, when a single item is described herein, morethan one item may be used in place of a single item. Similarly, wheremore than one item is described herein, a single item may be substitutedfor that more than one item.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

After reading the specification, skilled artisans will appreciate thatcertain features are, for clarity, described herein in the context ofseparate embodiments, may also be provided in combination in a singleembodiment. Conversely, various features that are, for brevity,described in the context of a single embodiment, may also be providedseparately or in any subcombination. Further, references to valuesstated in ranges include each and every value within that range.

The Abstract of the Disclosure is provided to comply with Patent Law andis submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description of the Drawings, various features maybe grouped together or described in a single embodiment for the purposeof streamlining the disclosure. This disclosure is not to be interpretedas reflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all features of any of the disclosed embodiments. Thus, thefollowing claims are incorporated into the Detailed Description of theDrawings, with each claim standing on its own as defining separatelyclaimed subject matter.

What is claimed is:
 1. A method for forming an abrasive articlecomprising: containing particles on an alignment structure; andexpelling particles from the alignment structure onto a backing using anelectrostatic force to project the particles from the alignmentstructure, across a gap between the alignment structure and the backingand onto the backing.
 2. The method of claim 1, wherein the particlesare abrasive particles.
 3. The method of claim 1, wherein the particlescomprise diluent particles.
 4. The method of claim 1, wherein thealignment structure comprises openings and at least some of the openingscomprise particles.
 5. The method of claim 4, wherein each opening ofthe openings has a size and shape configured to contain at least oneabrasive particle in a predetermined orientation.
 6. The method of claim1, wherein the alignment structure comprises a web, a fibrous material,a mesh, a solid structure having openings, a belt, a roller, a patternedmaterial, or any combination thereof.
 7. The method of claim 1, furthercomprising: expelling abrasive particles from the alignment structureonto a backing using an electrostatic force to project the abrasiveparticles from the alignment structure, across a gap between thealignment structure and the backing and onto the backing; and applyingdiluent particles onto the backing.
 8. The method of claim 7, whereinapplying diluent particles onto the backing is conducted via gravity. 9.The method of claim 7, wherein applying the diluent particles isconducted after expelling the abrasive particles.
 10. The method ofclaim 7, wherein applying the diluent particles is conducted beforeexpelling the abrasive particles.
 11. The method of claim 7, whereinapplying the diluent particles is conducted simultaneously withexpelling the abrasive particles.
 12. The method of claim 7, wherein theabrasive particles comprise shaped abrasive particles and the diluentparticles comprise crushed particles having random shapes.
 13. Themethod of claim 7, wherein the abrasive particles comprise abrasiveparticles having a random shape and the diluent particles compriseparticles having a random shape, wherein the diluent particles have anaverage particles size less than the average particle size of theabrasive particles.
 14. The method of claim 1, further comprising:expelling a first group of abrasive particles from the alignmentstructure onto a backing using an electrostatic force to project theabrasive particles from the alignment structure, across a gap betweenthe alignment structure and the backing and onto the backing; andapplying a second group of abrasive particles different than the firstgroup of abrasive particles onto the backing after expelling theabrasive particles from the alignment structure.
 15. The method of claim14, wherein the first group of abrasive particles comprises shapedabrasive particles.
 16. The method of claim 14, wherein the second groupof abrasive particles comprises shaped abrasive particles.
 17. Themethod of claim 14, wherein the first group of abrasive particlescomprises abrasive particles having a random shape.
 18. The method ofclaim 14, wherein the second group of arbasive particles comprisesabrasive particles having a random shape.
 19. The method of claim 14,wherein the first group of abrasive particles have a differentcomposition relative to the second group of abrasive particles.
 20. Themethod of claim 14, wherein the first group of abrasive particles havinga different two-dimensional shape relative to the second group ofabrasive particles.
 21. The method of claim 1, further comprisingplacing the particles on the alignment structure via vibration,adhesion, electromagnetic attraction, patterning, printing, pressuredifferential, roll coat, gravity drop, or any combination thereof. 22.The method of claim 1, wherein the backing comprises an adhesive and theparticles are adhered to the adhesive.
 23. The method of claim 1,wherein the particles comprise shaped abrasive particles having apredetermined two-dimensional shape in a dimension defined by the lengthand width of the particle.
 24. The method of claim 23, wherein thetwo-dimensional shape is selected from the group consisting of apolygon, an ellipsoid, a numeral, a Greek alphabet letter, a Latinalphabet letter, a Russian alphabet character, a Kanji character, acomplex shape including a combination of polygonal shapes, and acombination thereof.
 25. The method of claim 23, wherein the shapedabrasive particles have a triangular two-dimensional shape.
 26. Themethod of claim 23, wherein expelling a particle comprises: expelling afirst shaped abrasive particle onto the backing in a first position; andexpelling a second shaped abrasive particle onto the backing in a secondposition, wherein the first shaped abrasive particle and second shapedabrasive particle are arranged in a non-shadowing arrangement relativeto each other, the non-shadowing arrangement comprising at least two ofa predetermined rotational orientation, a predetermined lateralorientation, and a predetermined longitudinal orientation.
 27. Themethod of claim 23, further comprising: expelling a first group ofshaped abrasive particles onto the backing, wherein each of theplurality of shaped abrasive particles of the first group share at leastone of a predetermined rotational orientation, a predetermined lateralorientation, and a predetermined longitudinal orientation; and expellinga second group of shaped abrasive particles distinct from the firstgroup onto the backing, wherein each of the shaped abrasive particles ofthe second group share at least one of a predetermined rotationalorientation, a predetermined lateral orientation, and a predeterminedlongitudinal orientation.
 28. The method of claim 1, wherein alignmentstructure comprises a solid structure having openings, wherein theopenings are arranged in a predetermined distribution and the abrasiveparticles are arranged in a predetermined distribution within theopenings of the alignment structure.
 29. The method of claim 28, whereinexpelling the abrasive particles comprises expelling the abrasiveparticles on to the backing in a predetermined distribution.
 30. Themethod of claim 29, wherein the predetermined distribution of theabrasive particles on the backing is the same as the predetermineddistribution of the openings on the alignment structure.
 31. The methodof claim 1, wherein the adhesive layer comprises a patterned make coatcomprising a predetermined distribution of discrete adhesive regions andthe abrasive particles are adhered to the backing at the discreteadhesive regions.
 32. The method of claim 31, wherein the discreteadhesive regions are shaped and sized to accommodate a single abrasiveparticle.
 33. The method of claim 1, wherein the abrasive particles areshaped abrasive particles and at least about 80% of a total content ofthe abrasive particles are arranged in a side orientation relative tothe backing.
 34. The method of claim 33, wherein the shaped abrasiveparticle can be placed in a position having a predetermined verticalorientation and having tilt angle of at least about 45° and not greaterthan about 90°.
 35. The method of claim 1, wherein the abrasiveparticles are contained on the backing at a grain weight of at least 10lb/ream (148 g/m²).
 36. The method of claim 1, further comprising achannel region on the backing, wherein the channel region comprises aregion that is free of abrasive particles.
 37. The method of claim 36,wherein the channel region is patterned on the surface of the backing.38. The method of claim 36, wherein the channel region extends acrossthe backing and separates groups of abrasive particles.
 39. The methodof claim 36, wherein the channel regions define dedicated regionsbetween groups of abrasive particles, the channel region having a widththat is greater than a longitudinal space or a lateral space betweenadjacent abrasive particles in the groups.
 40. The method of claim 36,further comprising a plurality of channel regions extending across thebacking, wherein at least one of the channel regions of the plurality ofchannel regions extends along a direction that is parallel to alongitudinal axis of the backing.
 41. The method of claim 36, furthercomprising a plurality of channel regions extending across the backing,wherein at least one of the channel regions of the plurality of channelregions extends along a direction that is perpedicular to a longitudinalaxis of the backing.
 42. The method of claim 36, further comprising aplurality of channel regions extending across the backing, wherein atleast one of the channel regions has an axis extending along a center ofthe channel region, and wherein the axis is oriented at a predeterminedangle relative to a longitudinal axis of the backing.